CD4 and obesity due to melanocortin 4 receptor deficiency: A higher body mass index has been associated with higher counts of total leukocytes, total lymphocytes, CD4+ T cells, regulatory T cells (Van Der Weerd et al., 2012) and effector memory αβ T cells (Alam et al., 2012), most likely reflecting obesity-induced inflammation (Womack et al., 2007; Ilavská et al., 2012).