3/1/1986 - 7/17/1989 : Research Associate, Genetic Engineering Center, Korea Institute of Science and Technology (KIST), Seoul, Korea
9/1/1989 - 2/30/1994 : TA/RA, Department of Microbiology & Immunology, University of Illinois, USA
3/1/1994 - 3/31/1995 : Postdoctoral Fellow, Department of Microbiology & Immunology, University of Illinois, USA
4/1/1995 - 8/15/1996 : Postdoctoral Fellow, Division of Immunology, Stanford University, USA
7/1996 - 8/1996 : Visisting Professor, Stanford University, USA
6/13/1996 - 9/30/2000 : Assistant Professor, College of Pharmacy, Chonnam National University, Gwangju, Korea
10/1/2000 - 8/31/2005 : Associate Professor, College of Pharmacy, Chonnam National University, Gwangju, Korea
1/1/2004 - 8/31/2004 : Visiting Professor, College of Medicine, Univ. of Illinois at Chicago, Chicago, USA
9/2002 - 12/2003 : Lecturer (Immunology Class), College of Pharmacy, Chosun University, Kwangju, Korea
9/1/2005 - present : Professor, School of Life Sciences and Biotechnology, Korea University, Seoul, Korea
7/1/2007 - present : Vice Director, BK21 School of Life Sciences and Biotechnology, Korea University, Seoul, Korea
11/15/2001 - 8/31/2005 : 전남대학교 병원 조혈계질환 유전체연구센터 겸직교수
11/15/2002 - 1/2004 : 전남대학교 약품개발연구소장
9/1/2005 - 현재 : 고려대학교 생명과학부/생명공학원 교수
7/1/2007 - 7/31/2012 : 고려대학교 BK21 생명공학원사업단 부단장
8/1/2012 - 7/31/2014 : 고려대학교 생명과학대학 부학장
3/1/2013 - 7/31/2014 : 고려대학교 생명과학대학 생명과학계열학부 학부장