Author

Shen Yeh-Ying holds a PhD from the Chinese Studies Department at the National University of Singapore and is a social anthropologist. She is currently an adjunct lecturer at the Singapore University of Social Sciences. Her research focuses on the Chinese diaspora, Chinese folk religion, and women in Chinese religious traditions. Her primary fieldwork sites are Indonesia and Singapore. Her work has been published in journals such as Studies in Chinese Religions, Journal of Chinese Religions, and Reli-gions.

JDTREA 2026,5(2): 13–30

Introduction

Ethnic Chinese constitute a small minority in Indonesia. According to the 2010 national census conducted by the Indonesian Statistics Bureaucracy (Badan Pusat Statistik, BPS), ethnic Chinese accounted for approximately 1.2 percent of the population (around 2.83 million people) ( Databooks 2017 ; Cultural Atlas 2025 ). ¹ Historically, Chinese communities in Indonesia have experienced several severe waves of anti-Chinese violence, particularly the 30 September Movement events in 1965 and the May 1998 riots. After Suharto (1921–2008) launched a coup in 1965 and overthrew the founding president Sukarno (1901–1970), the subsequent establishment of the “New Order” (Orde Baru, 1966–1998) regime targeted Chinese people and Chinese culture, portraying them as aligned with the communist bloc. This period witnessed unprecedented suppression and restriction. Later, under the impact of the 1997–1998 Asian Financial Crisis, Chinese Indonesians once again became scapegoats and targets of violence.

Despite these historical challenges, several religious groups with Chinese origins or attributes emerged and developed in Indonesia, they even achieving recognition at the national level. The transformation from being marginalized and unrecognized to becoming locally adapted reflects the ongoing processes of negotiation and struggle within Chinese Indonesian communities. This article examines three Chinese-attributed religions—MATAKIN (Confucianism), Mile Dadao (also known as Maitreya Great Dao, 彌勒大道) and Yiguandao (also known as I-Kuan Dao, 一貫道)—in Indonesia, analyzing the factors that enabled them to take root in Indonesian society and the extent to which their transformed forms diverge from their original Chinese cultural foundations. It is natural that Chinese immigrants brought their own religious traditions with them. In Indonesia, besides the three Chinese religious movements discussed in this article, there are also other forms of folk worship, such as the local guardian deity Tua Pek Kong (大伯公, Dabogong), and Lord Guan (關聖帝君, Guansheng Dijun) ( Coconut Jakarta 2017 ). ² However, when speaking of religious traditions associated with Chinese cultural heritage, Confucianism occupies a central symbolic position. Based on this, this article focuses on these three Chinese-affiliated religions precisely because they all take the promotion of Confucian ethical and moral values as one of their core teachings. Other forms of folk worship lie beyond the scope of this study and are therefore not examined here.

While existing studies tend to focus on individual religious movements or broader ethnic politics, few offer a comparative analysis of how different Chinese-attributed religions adopted distinct localization strategies. This article seeks to address this gap by examining and comparing the adaptive trajectories of MATAKIN, Mile Dadao, and Yiguandao in Indonesia. The primary research materials for this study are based on my fieldwork and participant observations. Before discussing these three Chinese-attributed religions, I will first provide a basic historical overview of the suppression of Chinese culture during Suharto’s regime. This context helps illuminate why Chinese-derived religious traditions in Indonesia needed to undergo transformation and adaptation.

New Order: The Consolidation of Power

Indonesia’s New Order period (1966–1998), under the leadership of President Suharto, marked one of the most influential and deeply transformative eras in Indonesia’s modern history. The regime emerged from the upheaval of the 1965–66 political crisis, which included the alleged 30 September Movement (G30S) coup attempt, widespread anti-communist violence, and the collapse of Sukarno’s rule. Positioning itself as a response to the instability of the previous era, the New Order emphasized political order, rapid economic development, and a strong military presence in government. Through technocratic planning and closer ties to Western economies, Suharto reshaped Indonesia’s political institutions and reoriented its national priorities ( Roosa 2006 ).

The establishment of the People’s Republic of China in 1949 and Sukarno’s increasingly close relations with Beijing contributed to suspicions that ethnic Chinese Indonesians were politically aligned with communist forces. As anti-communist sentiment intensified in 1965, Chinese Indonesians were widely suspected of supporting the Indonesian Communist Party (PKI). Although the mass killings of 1965–1966 primarily targeted alleged communists rather than ethnic Chinese as an ethnic group, Chinese Indonesians were disproportionately affected and became especially vulnerable to violence, surveillance, and political repression. The New Order’s strong anti-communist stance, together with long-standing stereotypes of Chinese Indonesians as “outsiders,” resulted in wide-ranging assimilation policies. After 1965, the government imposed strict restrictions on Chinese cultural life, including bans on Chinese-language education and media, prohibitions on the public use of Mandarin and other Chinese dialects, and the closure of Chinese organizations. Public expressions of Chinese culture—such as Lunar New Year celebrations, temple activities, and the display of Chinese characters—were restricted or closely monitored. Ethnic Chinese were also encouraged to adopt Indonesian-sounding names and obtain special citizenship documents, reinforcing their marginal position within the nation ( Tsuda 2012 ).

At the same time, the regime maintained selective economic cooperation with a small group of wealthy Chinese Indonesian businessmen integrated into Suharto’s patronage networks. This created a paradoxical situation in which Chinese culture was suppressed while certain Chinese entrepreneurs became key partners in Indonesia’s high-growth economy. The regime’s decline became evident in the 1990s amid rising economic inequality, growing Islamic activism, and increasing demands for democratization. The 1997–1998 Asian Financial Crisis triggered widespread unrest and violent anti-Chinese riots in several cities. Under mounting political pressure, Suharto resigned in May 1998, marking the end of the New Order and the beginning of the Reformasi era.

The Three Chinese-Attributed Religions and Their Transformation Development

Among the three religious movements examined in this article, MATAKIN originated locally in Indonesia, whereas the other two—Mile Dadao and Yiguandao—were introduced from Taiwan.

MATAKIN

By the late nineteenth century, Indonesia’s Chinese community was mainly divided into two groups: the Peranakan, mostly of mixed heritage and born in Indonesia, who had largely adopted local customs, and the Totok, recent immigrants who still retained much of their Chinese culture. The Chinese population at that time was composed largely of Peranakan Chinese. Many of these Chinese Indonesians were no longer familiar with Chinese language or culture. Among them, several Western-educated intellectuals perceived the inequitable treatment imposed on the Chinese community by the Dutch colonial authorities. Inspired as well by the late Qing Chinese intellectual Liang Qichao’s (梁啟超, 1873–1929) advocacy of Confucian teachings as a means of self-strengthening, they jointly established the Tiong Hoa Hwee Koan (中華會館, zhonghua huiguan, hereafter THHK) of Batavia (the Batavia Chinese Association) in 1900-1901 as an institution dedicated to the promotion of Confucian philosophy. At the time, a Confucian revival movement was also gaining momentum in Singapore and Malaya, as overseas Chinese leaders believed that the rational spirit of Confucianism could help modernize China and unify overseas Chinese communities. Hence, the initial aim of THHK was to employ Confucian thoughts to improve the cultural identity and social position of Chinese Indonesians ( Coppel 1981 ; Kong 1989 ). THHK later became increasingly focused on establishing Chinese schools. As a result, other Confucian advocates stepped forward to form new organizations, such as the Khong Kauw Hwee (孔教會, the Confucian Association, kongjiao hui) founded in Solo in 1918. Similar Confucian associations soon emerged in other cities, including Surabaya, Semarang, and Bandung. In 1884, Chinese community leaders in Surabaya jointly funded the construction of a Wenchang Temple (文昌祠, wenchang ci). Wenchang is a traditional Chinese deity associated with literary talent and academic success. The temple later came to enshrine Confucius and became known as the Surabaya Boen Bio (文廟, Confucian Temple, wenmiao). The temple encouraged Chinese Indonesians to celebrate traditional festivals and hold religious rituals, thereby preserving Chinese cultural heritage. Over time, the Surabaya Boen Bio naturally developed into the base of the Surabaya Confucian Association ( Wang 2010 , 214–215).

To discourage younger generations from turning to Christianity or Islam, the Confucian associations worked to develop an institutional identity that resembled an organized religious movement. In line with this aim, the Surabaya Confucian Association published a journal introducing Confucian teachings titled Djiep Tik Tjie Boen (入德之門, the gateway to moral cultivation, rude zhimen). In 1923, during a congress of Confucian adherents in Yogyakarta, participants decided to establish the Khong Kauw Tjong Hwee (孔教總會, Confucian General Organization, kongjiao zonghui, thereafter KKTH) and the office was based in Bandung. While the Organization undertook the Indonesian translation of the Four Books (四書, sishu), internal debates soon emerged across generations regarding how these texts should be interpreted. As Charles Coppel notes, although Chinese Indonesians at the time generally acknowledged Confucius as a figure of supreme, almost prophetic status, their interpretations of the Four Books diverged into three distinct approaches. The first group accepted only the traditional commentaries passed down from the Qing dynasty; the second adopted a more mythologized reading of the texts; and the third—predominantly younger members—presented the Four Books through dance and music, treating them as a form of classical artistic performance ( Coppel 1981 , 192–193). These differences reveal not only the community’s limited familiarity with the original cultural context of Chinese Confucianism but also their attempts to reinterpret and integrate Confucian teachings in ways that resonated with the Indonesian social environment.

Over time, the KKTH also developed a clerical structure to promote and institutionalize Confucianism. However, even though positions resembling clergy had begun to emerge, the Confucian Associations at this stage had not yet explicitly defined themselves as a religion in their statutes. Most of their regulations focused instead on ethical teachings and on standardizing traditional Chinese practices such as weddings and funerals ( Coppel 1981 , 192–194; Wang 2010 , 215). The 1930s was a politically turbulent decade in the Dutch East Indies, shaped by the global economic depression, intensified nationalist movements, and tightening colonial control, all of which pushed various ethnic and religious communities—including Chinese groups—to reorganize and redefine their cultural identities ( Ricklefs 1981 ). Due to the loose organizational structure of the KKTH, it struggled to coordinate the various local Confucian associations. In the 1930s, a group of active Chinese reformers emerged in Solo, who hoped to establish a more effective central body capable of unifying Confucian associations across the country. Thus, in 1938, various local Confucian associations convened in Solo and established a new Confucian General Council. Later, the development of the Confucian General Council made little progress during World War II. After Indonesia gained independence, the rise of Indonesian nationalism further pressured the Confucian General Council to embark on a process of Indonesianization ( Wang 2010 , 215–216).

In Indonesia, religion occupies a central place in both public life and state governance, largely due to the national ideology of Pancasila. As the foundational framework of the Indonesian state, Pancasila comprises five principles, the first of which—‘Belief in the One and Almighty God’—establishes religious affiliation as a core marker of national identity and civic belonging. Although Pancasila does not mandate adherence to any specific faith, citizens are expected to identify with one of the state-recognized religions, which in turn structure key aspects of civil administration, including marriage registration, education, and legal documentation. It was in this religious and administrative context that the Confucian General Council in Indonesia undertook efforts to institutionalize Confucianism as an organized religion, seeking legal recognition, cultural protection, and full participation in the religiously structured framework of Indonesian society. In 1955, they attempted to rename the council Perserikatan Kung Chiao Hui Indonesia (孔教聯合會, federation of Confucian associations, kongjiao lianhehui), and later, in 1963, finally adopted the title Agama Khonghucu ( Wang 2010 , 216). In Indonesian, the term Agama refers to “religion”. This marked a significant transformation, formally redefining the Confucian General Council as a religious body. Originally, titles of the Confucian publications, as well as the institutional names mentioned in the previous paragraphs, were Hokkien romanization. Renaming these institutions and publications into Indonesian became an important strategy for localization. The subsequent efforts to institutionalize Confucianism received recognition from President Sukarno. In 1965, Sukarno issued Presidential Decree No. 1, which designated Agama Khonghucu as one of Indonesia’s six official religions. ³ Sukarno did so in order to balance the opposing forces of the right-wing military and the left-leaning Indonesian Communist Party (PKI). In the political landscape of 1960s Indonesia, the PKI promoted secular and atheistic principles, which clashed with the state ideology of Pancasila—particularly its first principle, belief in a supreme God. By strengthening the public role of religion and institutionalizing multiple faiths, including Agama Khonghucu, Sukarno reinforced Pancasila as the ideological foundation of the nation. This strategy not only curtailed the influence of the PKI but also prevented the military from monopolizing anti-communist legitimacy ( Ricklefs 1981 ).

Following the 30 September Movement in 1965, Suharto—a right-wing military general—came to power, and PKI was dismantled. In order to eradicate left-wing influence and prevent PKI from re-emerging, Suharto continued to promote and strengthen religious institutions. Various religions in Indonesia, including Agama Khonghucu, entered a period of unprecedented development. Sensing the political climate, the Confucian community adapted accordingly. At its 1967 national congress, it adopted the new name Majelis Tinggi Agama Khonghucu Indonesia (MATAKIN). During this period, MATAKIN established detailed religious regulations and ritual systems, effectively transforming itself into a full-fledged religion. MATAKIN identifies Thian (天, Heaven, tian) as the sole supreme deity and regarded Confucius as a prophet. Confucian places of worship is called lithang (禮堂, ritual halls, litang), where a statue or an image of Confucius is enshrined for veneration. The clergy are organized into three ranks: Hak Su (學士, Xueshi), Bun Su (文士, Wenshi), and Kauw Seng (教生, Jiaosheng). Unsurprisingly, the language used within MATAKIN is entirely Indonesian. Rituals typically begin with the singing of hymns, followed by sermons delivered by clergy. Adherents are expected to abide by the Five Constants (五常, wuchang) and the Eight Virtues (八德, bade), both of which constitute foundational principles within Confucian thoughts ( Suryadinata 2002 , 54–57). These features show clear parallels with monotheistic traditions (such as Christianity and Islam) and illustrate how Confucianism was localized and reshaped in the Indonesian context.

From its initial establishment within THHK, through its subsequent historical transformations to the present, MATAKIN was sustained primarily by the Peranakan Chinese. Notably, the Peranakan generally had limited proficiency in Chinese and little understanding of the substantive content of the Confucian classics. Yet they consistently insisted on the continued existence and local adaptation of MATAKIN. This situation reveals a disjunction between linguistic competence and classical knowledge on the one hand, and the persistence of MATAKIN on the other. Rather than a transmission of Confucian doctrine, MATAKIN thus functioned primarily as a symbolic site for articulating and maintaining Chinese cultural identity in Indonesia.

Mile Dadao

Before discussing Mile Dadao, it is necessary to trace the early history of Yiguandao’s transmission to Indonesia, as Mile Dadao emerged as a branch of Yiguandao. Yiguandao was first introduced to Indonesia in 1950 by a Taiwanese missionary, Chen Boling (陳伯齡, ?–1984). In the aftermath of Japan’s defeat in World War II and its withdrawal from Taiwan in 1945, followed by the conclusion of the Chinese Civil War in 1949, Yiguandao missionaries from mainland China relocated to Taiwan between 1945 and 1950. It was during this period that Chen Boling was initiated into Yiguandao in Taiwan. Previously, Chen had worked as a doctor under Japanese colonial rule and was later conscripted by the Japanese military as a medical officer in Indonesia, where he married a Chinese Indonesian woman. These transregional experiences shaped both his personal trajectory and his subsequent religious activities. In 1950, Chen returned to Malang, East Java, with the intention of propagating Yiguandao. Fluent in Hokkien, Mandarin, and Indonesian, Chen was able to communicate effectively with Chinese Indonesian communities at a time when Chinese languages were still widely used, prior to the New Order’s assimilationist policies. This linguistic competence, combined with his familiarity with local social contexts, facilitated the rapid expansion of Yiguandao. Over the following two decades, Chen and his followers established more than 200 Yiguandao buddha halls (佛堂, fotang) across Indonesia’s major islands ( Shen 2022 , 223–224).

Pierre Bourdieu conceptualizes religion as a structured field in which various forms of capital—social, cultural, and symbolic—are accumulated, transmitted, and converted across generations of actors ( Bourdieu 1986 , 241–260). From this perspective, religious continuity is not merely doctrinal but is embedded in networks, authority structures, and embodied practices that constrain and enable later transformations. Empirical studies of Chinese religious movements further substantiate this view. David Palmer’s analysis of qigong (氣功) organizations in contemporary China demonstrates how new religious and spiritual movements often emerge as organizational descendants of earlier networks, inheriting personnel, practices, and modes of legitimacy while adapting to shifting political and regulatory environments ( Palmer 2007 ). Returning to the case of Mile Dadao, although it is not recognized as a legitimate lineage by contemporary Yiguandao authorities and is often regarded as having seceded from the orthodox transmission, it nonetheless inherited substantial local religious capital in Indonesia. Drawing on Bourdieu’s notion of the religious field, institutional continuity does not necessarily imply the inheritance of doctrinal orthodoxy, but rather the transmission of social, symbolic, and organizational capital accumulated within a specific historical context. Based on my fieldwork, this continuity is materially and symbolically expressed in the public buddha halls of Mile Dadao, where photographs of Chen Boling are displayed, and in historical narratives that situate Chen as a foundational figure in the Indonesian transmission of the faith. Such practices reflect not doctrinal continuity but a localized reconfiguration of religious memory, enabling Mile Dadao to claim legitimacy within the Indonesian religious field despite its contested status in transnational Yiguandao orthodoxy.

Mile Dadao was able to survive the New Order period largely because of its effective localization strategies. These included the exclusive use of Indonesian in religious activities, as well as the institutional and social foundations previously established by Chen Boling. Building upon these foundations, Mile Dadao further adapted to the Indonesian context by actively engaging in the fields of education and public welfare—domains that have long been central to religious legitimacy in Indonesian society. In Indonesia, due to the limited resources of the government, religious organizations have been expected to participate in the provision of education in order to ensure broader access to compulsory schooling. Consequently, the establishment and operation of schools by major religious groups in Indonesia is a common and institutionalized practice. In this regard, building upon these foundations, Mile Dadao further adapted to the Indonesian context by establishing schools. My fieldwork further indicates that Mile Dadao’s activities extended beyond formal education. Its “Happy Nature Exercise” program (大自然快樂操, daziran kuailecao), which emphasizes collective harmony and happiness, has been incorporated into local Indonesian primary and secondary school settings, allowing the movement to circulate in secular educational spaces without overt religious labelling. ⁸ In addition, Mile Dadao developed large-scale religious parks in cities such as Medan and Batam. Designed as recreational spaces featuring landscaped gardens, monumental architecture, vegetarian restaurants, cafés, and souvenir shops, these sites deliberately blurred the boundary between religious space and leisure space.

By downplaying explicit religious markers and emphasizing vegetarianism, aesthetics, and cultural consumption, Mile Dadao presented itself as socially beneficial, culturally embedded, and compatible with Indonesia’s broader framework of development and pluralism, thereby enhancing its capacity for sustained local adaptation in Indonesia.

Yiguandao

In this section, Yiguandao refers specifically to the new wave of missionaries who arrived in Indonesia around the 1990s. During the New Order period, anti-Chinese policies in Indonesia significantly reduced the willingness of missionaries from Taiwan to engage in proselytization. It was not until the later years of the New Order, when economic development accelerated and restrictions on Chinese culture were gradually relaxed, that conditions became more favorable. At the same time, Taiwan’s “Southbound Policy” (南向政策, nanxiang zhengce) encouraged Taiwanese businesses to invest in Southeast Asia. Within this broader political and economic context, Yiguandao missionaries followed these transnational flows and expanded their activities across Southeast Asia, including Indonesia. Based on my fieldwork, this later cohort of missionaries differed markedly from Chen Boling’s generation in their approach to localization. While these missionaries did learn Indonesian in order to communicate with the society, they consciously retained the use of Mandarin within the religious community, including in ritual formulas and everyday interaction. After nearly three decades of restrictions on Chinese language education, many Chinese Indonesians had lost proficiency in Chinese and familiarity with Chinese traditions. In response, these missionaries undertook systematic efforts to teach Mandarin and reintroduce elements of Chinese culture to their followers from the ground up.

After the repeal of anti-Chinese legislation in 1999, Yiguandao in Indonesia increasingly reframed itself as a vehicle for the revival and transmission of Chinese culture. This repositioning coincided with the rising global prominence of China, which generated growing local interest in learning Chinese language and culture ( Hoon 2012 , 88–96), thereby providing Yiguandao with new opportunities for expansion. In 2005, Yiguandao established the Majelis I-Kuan Dao Indonesia after receiving a verbal assurance from the Minister of Religious Affairs that it would be registered as an official religious body. However, due to bureaucratic ambiguity, the registration process was never formally completed, leaving the organization in an ambiguous legal position. As a result, Yiguandao temples encountered recurring difficulties at the local level: some regional authorities refused to acknowledge the organization’s legitimacy, while others classified its Buddha halls as illegal following reports filed by members of competing religious groups, notably Mile Dadao. These challenges constrained Yiguandao’s ability to operate openly. It was not until 2014, under the leadership of a new chairman with stronger connections to government institutions, that Yiguandao successfully registered under the name Majelis Agama Buddha I-Kuan Dao Indonesia. ⁹ This case illustrates how Indonesia’s bureaucratic structures shape the trajectories of transnational religious movements, particularly those perceived as foreign. It also highlights how interreligious competition within the Chinese Indonesian religious field can generate additional obstacles for newer or less institutionally entrenched groups.

As noted earlier, religion occupies a central position in Indonesian social life. For a marriage to be legally recognized, couples must not only register with the Ministry of Home Affairs but also conduct a religious wedding ceremony. In response, Yiguandao temples in Indonesia have incorporated religious wedding rites into their public activities—a practice that is uncommon in other national contexts. Furthermore, because the Indonesian state encourages religious organizations to establish educational institutions in order to alleviate pressures on public education, Yiguandao has also founded schools in Indonesia, currently operating mainly at the kindergarten and elementary levels in a limited number of cities ( Shen 2022 , 238–239). Nevertheless, Yiguandao’s engagement in educational provision remains far more modest than that of Mile Dadao. This disparity reflects the relatively weaker institutional foundations and social networks that Yiguandao has been able to establish vis-à-vis the Indonesian state and society, particularly when compared to Mile Dadao’s deeper historical roots and more extensive localization strategies.

Conclusion

This article has examined how three Chinese-attributed religious movements—MATAKIN, Mile Dadao, and Yiguandao—have been variously reconfigured in Indonesia through distinct strategies of localization, institutional adaptation, and engagement with the state and society. Rather than treating localization as a linear or uniform process, the Indonesian cases demonstrate that religious adaptation is contingent upon historical timing, political regimes, linguistic regimes, and pre-existing social networks.

MATAKIN represents the most extensive form of institutional and symbolic localization. From its early development among Peranakan Chinese to its eventual recognition as Agama Khonghucu, MATAKIN was transformed from a cultural-philosophical tradition into a formally institutionalized religion. This transformation was closely tied to Indonesia’s political structure, particularly the centrality of religion under Pancasila. By adopting monotheistic elements, clerical hierarchies, standardized rituals, and exclusive use of Indonesian, MATAKIN redefined itself in ways that aligned with state expectations, thereby securing legal recognition and long-term legitimacy. Mile Dadao exemplifies a different mode of adaptation, one that foregrounds social embeddedness and institutional continuity. Building upon the foundations laid by the Yiguandao missionary Chen Boling, Mile Dadao emphasized Indonesian-language practice, educational institutions, and large-scale religious parks that blurred the boundaries between religious space, leisure, and civic life. Its strong engagement in education, wellness activities, and public-facing infrastructure enabled the movement to present itself as socially beneficial and developmentally compatible, particularly during and after the New Order period. This strategy effectively softened the visibility of “foreign religion” while embedding Mile Dadao within everyday Indonesian social life.

Yiguandao, by contrast, adopted a strategy of selective localization. While later missionaries actively learned Indonesian and complied with local legal and social requirements—such as conducting religious weddings and operating schools—they simultaneously preserved Mandarin and Chinese ritual language within internal settings. Based on fieldwork, this dual linguistic strategy transformed Chinese language competence into a marker of orthodoxy and transnational legitimacy, particularly in relation to Taiwanese headquarters. Such positioning reflects a conscious response to Indonesia’s post–New Order political climate, in which Chinese culture became increasingly visible but foreign religious affiliations still required careful negotiation. Compared to Mile Dadao, Yiguandao’s weaker institutional embeddedness limited its capacity in areas such as education, revealing how uneven social foundations shape divergent adaptive outcomes.

Taken together, these cases illustrate that religious localization in Indonesia is not merely a matter of cultural translation, but a dynamic process of repositioning religious cores and boundaries within shifting political, linguistic, and social structures. The diverse trajectories reveal how Chinese religious movements recalibrated their cores and boundaries in response to Indonesia’s evolving religious landscape, producing multiple, locally grounded forms of religious life rather than a single model of adaptation.

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Notes