Although CXCL14-deficient (CXCL14−/−) mice do not display severe defects in their immune systems [5], we recently found that CXCL14−/− female mice weigh significantly less than wild-type mice and are protected from obesity-induced hyperglycemia, hyperinsulinemia, hypoadiponectinemia, and insulin resistance [6]. This evidence concerns the gene CXCL14 and obesity due to melanocortin 4 receptor deficiency.