Professor Dae Hyun Yoo has been working for the Hanyang University Hospital for Rheumatic Diseases since 1992. After research fellowship at the Hospital for Special Surgery, he worked on SLE pathogenesis and clinical issues. Currently, he is interested in the utility of biologic agents for rheumatoid arthritis, pathogenesis and biomarkers of adult onset Still’s diseases, diagnosis and management of idiopathic inflammatory myositis. For recent 15 years, he has focused on the utility of biosimilars for the treatment of rheumatic diseases. In addition, he served for APLAR as scientific committee chair, vice president, and associate editor of international journal of rheumatic disease. Also he contributed significantly for the development of Korean College of Rheumatology as president and chair of the board.