Despite the potential protective role of IL-17 in maintaining intestinal homeostasis during HFD [4, 5], elevation of IL-17 is also associated with obesity-related rheumatoid arthritis, multiple sclerosis, psoriasis, and cancer [53], suggesting that a delicate IL-17 site-specific balance is required to achieve homeostasis. This evidence concerns the gene IL17A and obesity due to melanocortin 4 receptor deficiency.