IGF1 and obesity due to melanocortin 4 receptor deficiency: In the periphery, adipokines can contribute to a chronic, low-grade, obesity-related inflammatory state, which leads to insulin resistance and hyperinsulinemia that indirectly contributes to myelomagenesis through the action of bioavailable insulin [52] on circulating endogenous growth factors (insulin-like growth factor [IGF]) [53], and their binding proteins [54].