However, besides the CCR2 level, DARC+Ly6Clo ATMs express a higher level of IL-10, IDO, and TGF-β mRNA than those of DARC- cells, indicating that the DARC+Ly6Clo cells essentially function to revert the inflammatory status in diet-induced obesity to an anti-inflammatory status. Here, IDO1 is linked to obesity due to melanocortin 4 receptor deficiency.