Several signaling pathways, including nuclear factor-κB (NF-κB), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase pathways, are activated by CD40 ligation; however, there is a differential outcome depending upon which TRAF member binds preferentially, and which cell/conditions are involved [31]; the binding of TRAF-6 is critical in vascular inflammation and metabolic complications associated with obesity [32,33]. This evidence concerns the gene CD40 and obesity due to melanocortin 4 receptor deficiency.