IL1B and obesity due to melanocortin 4 receptor deficiency: IL-1β, IL-8, and CCL20 are among the few cytokines produced by enterocytes in the absence of crosstalk from immune cells.42 ELISA-based quantification of these cytokines in basolateral supernatants resulted in minimal or no detection in any experimental group (Supplemental Figure S6b-d), suggesting that epithelial cross-talk with immune or microbial cells may be necessary to induce inflammatory responses associated with increased obesity risk.