Like other CD4 T helper cell subsets, Treg CD4+ T cells express CCR5, are readily infected in untreated HIV infection (145) and in PLWH on ART, can harbor replication competent virus (139); with some reports that Treg CD4+ T cells are enriched for latent HIV relative to conventional T helper subsets [reviewed in (146)]. Here, CD4 is linked to HIV infectious disease.