Of the initial set of 8 HIV-1 candidate polypeptide antigens evaluated, 5 (gp41 endodomain [gp41e], integrase p31 [p31], matrix antigen p17 [p17], protease [PR], and Nef) were found to elicit little or no immunoreactivity in individuals (n = 10) vaccinated with the mosaic-based HIV-1 vaccine regimen (from the TRAVERSE and ASCENT studies [19, 20]) but were reactive in at least half of individuals (n = 10) with known HIV-1 infection (Fig. 1A to C). This evidence concerns the gene S100B and HIV-1 infection.