CD4 T cell death occurs after cellular infection with HIV (Westendorp et al., 1995), or in bystander or incompletely infected cells due to activation of cellular defense programs (Doitsh et al., 2010; Doitsh et al., 2014), and is halted and, to some extent, reversed by antiretroviral therapy (ART), even sub-optimal therapy (Jackson et al., 2018). The gene discussed is CD4; the disease is infection.