The long-term, stable viral population – the rebound competent viral reservoir (RCVR) – that can re-ignite infection post-ART is complex and includes multiple subsets of CD4+ T cells, particularly including clonal expansions of CD4+ memory T cells, and possibly macrophages, that are widely distributed throughout the lymphoid tissues of the body2,4,6–10. This evidence concerns the gene CD4 and infection.