In a prospective cohort with a two-year follow-up, Hoffman et al. observed that patients aged 50 years and over presented a poor CD4 response to ART, thus corroborating the present findings, as well as a lower frequency of naive CD4 cells and higher number of memory CD4 cells in the pre-ART treatment assessment period, suggesting that the progression of HIV-infection is associated with a depreciation of naive CD4 cells and a lower response to ART [3]. The gene discussed is CD4; the disease is HIV infectious disease.