What HIV Needs (IMAGE) Salk Institute Caption The human immunodeficiency virus only brings along a minimalist's survival gear -- just nine genes, coding for 15 proteins -- and relies on its host cell to provide what's missing. Credit Dr. John Young, Salk Institute for Biological Studies Usage Restrictions For one time use only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.