Historical observations on the half-century freeze in research between the Bonghan system and the primo vascular system.

This article provides potential reasons for the past 45-year halt in research between the time of the Bonghan system of Bong Han Kim (B.H. Kim) and that of the primo vascular system (PVS) of Kwang-Sup Soh (K.S. Soh), briefly but more accurately in its history. Over the years, numerous questions related to the Bonghan system and the PVS have arisen, especially from researchers interested in pursuing PVS research: When and how did B.H. Kim's study results on the Bonghan system become known to public? Why did B.H. Kim and his publications disappear after 1966? Why was little study performed on the system for almost 50 years after Kim? Why and how was the research on the system reinitiated in 2002 by Kwang-Sup Soh? Why did the Bonghan system become the PVS? These questions, as well as technical difficulties in identifying the system, have discouraged many researchers from becoming involved in research on the system. The motivation for preparing this article was to remove doubts about the existence of this important organ, which might have been caused by its unusual and unclear historical background, by providing an accurate history.