The proinflammatory factors produced by M1-like macrophages, such as TNFα and IL-1β, are increased in islets in obesity and T2DM, and they decrease GSIS by inducing NF-κB or JNK activation in β cells after 16 or 24 h of treatment8,14,15. The gene discussed is IL1B; the disease is obesity due to melanocortin 4 receptor deficiency.