Nevertheless, in macrophages derived from PP cells, the gene expression of CCL2 (Ccl2) and TNF (Tnf) was upregulated by dietary-induced obesity (Figures S4E, G), suggesting that intestinal inflammation was already elicited in the small intestinal compartment, although there was no detected change in the gene expression of IL-1β (Il1b) and IL-6 (Il6) in PP macrophages (Figures S4F, H). Here, IL1B is linked to obesity due to melanocortin 4 receptor deficiency.