In this study, arsenic class of mineral, arsenic trioxide, clinically approved for treating acute promyelocytic leukemia, is demonstrated to reactivate latent provirus in CD4+ T cells from HIV‐1 patients and Simian immunodeficiency virus (SIV)‐infected macaques, without significant systemic T cell activation and inflammatory responses. The gene discussed is CD4; the disease is acute promyelocytic leukemia.