CXCR2 and obesity due to melanocortin 4 receptor deficiency: Specifically we show that CXCR2 KO female mice have smaller adipocytes in several different fat depots, possibly because of aberrant expression of CXCR2‐regulated adipogenesis related genes.24 Our findings may, at least in part, explain CXCR2 KO mouse protection from obesity‐induced insulin resistance.25 Overall the results presented broaden our understanding of the role of the chemokine system in adipose tissue regulation and add to the developmental processes in which chemokines play a role.