Moreover, ILC2s secrete IL-13 and activate M2-like macrophage, whereas ILC1s secrete IFN-γ, inhibit activation of ILC2s and M2-like macrophages, and promote M1-like macrophages in WAT (29), which may promote the inflammatory state in obesity (15). The gene discussed is IFNG; the disease is obesity due to melanocortin 4 receptor deficiency.