CD4+ T cells are reported to retain immunological memory of obesity status (44), thus we hypothesized that since CD4+ T cells from obese PLWH are exposed to higher circulating leptin levels in vivo, it is likely that immunological memory of this high leptin abundant environment may differently effect CD4+ T cell activation and effector responses following ex vivo stimulation. This evidence concerns the gene CD4 and obesity due to melanocortin 4 receptor deficiency.