During the first 6 months of infection both subjects mounted T cell responses to multiple epitopes in the relatively conserved viral proteins Gag and Pol (7/12 of the epitope-containing regions recognized by R880F and 8/13 of those recognized by R463F), and both also exhibited 2 (R880F) or 3 (R463F) Env-specific responses, 1 Nef-specific response and 2 (R880F) or 1 (R463F) response to epitope-containing regions in other viral proteins. This evidence concerns the gene S100B and infection.