The UFO Study is a constellation of research studies and projects focusing primarily on viral hepatitis, specifically hepatitis C virus (HCV), among young people who inject drugs (PWID) in San Francisco. The UFO study is based at the University of California, San Francisco (UCSF), beginning in 1997 and continues to this day. We have conducted our community based research in many different neighborhoods since then, and have called the Tenderloin District our home for 10 years. We are currently located at 964 Market Street at the Tenderloin Clinical Research Center (TCRC).