ACKNOWLEDGMENTS
We thank Eun Kyung Choi (Department of Pathology, Seoul National University Hospital) for her technical assistance in electron microscopy. Disclosure: The authors have no potential conflicts of interest to disclose.
Author Contributions: Conceptualization: Oh MD, Park WB.
Data curation: Park WB, Kwon NJ, Choi SJ, Yun J, Lee GW, Kim JY.
Formal analysis: Oh MD, Park WB, Seong MW, Kim NJ, Seo JS.
Writing - original draft: Park WB, Kwon NJ, Kang CK.
Writing - review & editing: Seong MW, Choe PG, Kim NJ, Oh MD.