The untreated HIV-infected subjects without overt neurological disease (referred to as neuroasymptomatics, NA) were stratified by blood CD4+ T cell counts and included: 53 subjects with CD4+ counts <50 cells/μL (mean age 38.9); 69 subjects with CD4+ counts 50-199 cells/μL (mean age 38.6); 69 with counts 200-349 cells/μL (mean age 38.8); and 108 with CD4+ counts >350 cells/μL (mean age 37.5). This evidence concerns the gene CD4 and nervous system disorder.