Our observations regarding the beneficial effects of IAP are supported by earlier reports that a reduced expression of IAP was found in IBD, metabolic syndrome, cystic fibrosis, necrotizing enterocolitis, and diabetes [19,28,31,32], and IAP deficiency has been linked with obesity and IBD [10,28,33,34]. Here, ALPI is linked to obesity due to melanocortin 4 receptor deficiency.