Dr. Dae Hyun Yoo is professor of Rheumatology at Hanyang University Hospital for Rheumatic Diseases, Seoul, Republic of Korea. Dr. Yoo graduated from Hanyang University Medical College, and trained at the department of Internal Medicine and Rheumatology of Hanyang University Hospital. Prof. Yoo was recruited as a faculty of Hanyang University, and took part in basic research for two years at the Hospital for Special Surgery in New York city. Also, he served to scientific society as a vice-president of APLAR, chair of the board and president of Korean College of Rheumatology. He has been interested in cytokine balance in autoimmune diseases, the utility of biosimilars in rheumatic diseases, management and biomarkers of adult onset Still’s disease, and inflammatory myositis.