1983–1986 Researcher, Genetic Eng. Center, KAIST, Korea 1991–1994 Post-doc, MIT, USA 1993–1994 Senior Scientist, Cubist Pharmaceuticals, USA 1994-2001 Associate Professor, Sung Kyun Kwan University, Korea 2001-present Professor, College of Pharmacy, Graduate Program in Bioinformatics , Genetic Engineering, Cancer Biology, Seoul National Univ. 1998-present Director, Center for Medicinal Protein Network and Systems Biology, Seoul National University 2008- Director, Information Center of Bio-pharmacological Network 2008- Director, Integrated Bioscience and Biotechnology Institute

• Catalysis.- Emergence and Evolution.- Architecture.- Protein-protein Interactions and Multicomponent Complexes.- Interactions with RNAs.- Secretion and Circulation.- Regulatory Roles.- Neural Diseases.- Cancer.- Immune Diseases.- Pathologic Implications of Mitochondrial tRNA Synthetases .- Infectious Diseases.- Reprogramming of Genetic Code.- Novel functions of tRNAs.- Perspectives for Systems and Synthetic Bio-Medicine.