IFNG and obesity due to melanocortin 4 receptor deficiency: To validate that adipose ILC1s-derived IFN-γ was responsible for adipose tissue fibrogenesis and glycemic intolerance in obesity, we adoptively transferred adipose ILC1s from HFD-fed Ifng−/− mice or wild-type mice into Prkdc−/−IL2rg−/− mice and fed HFD for 6 weeks (Fig. 5a).