Obesity has been widely associated with systemic and adipose tissue inflammation with accumulating pro-inflammatory T cells, including cytotoxic CD8+ T cells, CD4+ type 1 helper T cells (Th1), CD4+ type 3/17 helper T cells (Th17), and memory B cells that exacerbate inflammation through the recruitment of chemokines, initiating an inflammatory process that promotes insulin resistance [6–10]. The gene discussed is CD4; the disease is obesity due to melanocortin 4 receptor deficiency.