IL22 and obesity due to melanocortin 4 receptor deficiency: During obesity, the pro-inflammatory skewing of immune cells favors the release of cytokines such as TNF and IFNγ, coupled with a reduction in IL-10, IL-17, and IL-22, resulting in reduced expression of epithelial tight junction proteins, mucin, and antimicrobial proteins such as RegIIIγ2,33.