Upon completion of his doctorate in Biochemistry at the Purdue University in 1993, Dr. Choi performed research involving cell signaling at the Harvard Medical School as a postdoctoral fellow. Since after 1995, he has been working as a professor of the Biotechnology Department of Yonsei University, Seoul, Korea. During the period, He served as a chief of the National Research Laboratory of the Molecular Complex Control and as a director of the Translational Research Center for Protein Function Control, a government supported drug development institute. Currently, he is a CEO of CK Regeon Inc, a company developing drugs regenerating damaged tissues of patients by safe targeting the WNT pathway.