Our cohort does not allow for an evaluation of starting ART in patients with baseline CD4+ cell counts ≥350 cells/μl because AfA guidelines only allow these patients to start ART following an AIDS-defining illness or with other serious co-morbidity: costs were actually higher in this group compared with those starting ART with baseline CD4+ cell counts 200–349 cells/μl, presumably reflecting the costs of treating the morbidity that was the criterion for starting ART. This evidence concerns the gene CD4 and AIDS.