Hiroyuki Gatanaga is an infectious diseases physician and has a special interest in HIV medicine. He joined AIDS Clinical Center (ACC) at the National Center for Global Health and Medicine (NCGM), Tokyo, Japan, as a staff physician since 2002, after a three year’s visiting fellowship at Experimental Retrovirology Section, National Cancer Institute/NIH, USA, where he studied drug resistance mechanism in HIV. His current position is Director, ACC/NCGM, and a Visiting Professor, Kumamoto University. His research interests include drug resistance and comorbidities in HIV-infected patients.