Nadir CD4+ T cell counts (12, 13), longer duration of HIV-1 infection (14, 15), microbial translocation and inflammation (1, 16), HIV-1 DNA persistence as well as PD-1 and TIGIT expression in long-lived CD4+ T cells (17), and poor responses to IL-7 and IL-15 (7–10, 17) have all been associated with failure to restore CD4+ T cell numbers in INR patients. The gene discussed is CD4; the disease is HIV-1 infection.