ANXA1 and obesity due to melanocortin 4 receptor deficiency: How and if ANXA1 is involved in such pathways remains speculative, but our preliminary data suggests that ANXA1 null mice exhibit greater cerebral perivascular CD45+ cell accumulation in response to diet-induced obesity than their wild-type counterparts, indicating a role for the protein in the regulation of immune cell entry into the brain, and further supporting our hypothesis that ANXA1 acts to protect BBB integrity.