CD4 and obesity due to melanocortin 4 receptor deficiency: The last one is strongly influenced by weight gain and obesity resulting in a shift from a homeostatic regulatory environment comprising M2-macrophages, eosinophil granulocytes, NKT cells, and CD4+ Treg toward a more pro-inflammatory environment characterized by a dominance of M1 macrophages and a T cell compartment altered toward CD4+ Th1 and CD8+ cytotoxic subtypes.