POMC and obesity due to melanocortin 4 receptor deficiency: In diet-induced obesity, elevated activation of inflammatory pathways such as nuclear transcription factor-kappaB (NF-kB) and inhibitors of nuclear factor kappa-B kinase β (IKKβ) induce levels of suppressor of cytokine signaling-3 (Socs3) mRNA in POMC neurons and disrupt leptin/insulin signalling, leading to the development of insulin/leptin resistance in obesity [121,122].