Gallo, Popovic, and colleagues demonstrated that a retrovirus they had isolated, called HTLV-III, was the cause of AIDS.  M. G. Sarngadharan, and E. Read. Bibcode:1984Sci...224..497P. doi:10.1126/science.6200935. PMID 6200935. This is the first of 4 related papers that Gallo's team published in Science in May 1984. In 1986 Gallo received his second Lasker Award, “For determining that the retrovirus now known as HIV-1 is the cause of Acquired Immune Deficiency Syndrome (AIDS)."