Itis plausible that functional variation in mtDNA would influence T cell dynamics suchas apoptosis in response to environmental stressors (e.g. HIV infection and/or ART).We hypothesized that among individuals with control of HIV replication followinginitiation of ART, mtDNA variation would influence CD4 count recovery throughmechanisms that modulate the efficiency of CD4 cell proliferation, one of thesebeing T cell activation. The gene discussed is CD4; the disease is HIV infectious disease.