Under oxidative stress, FABP4 undergoes a conformational change that increases its affinity for palmitic acid, a saturated fatty acid (Furuhashi et al. 2016) and obesity is accompanied by oxidative stress in adipose tissue: thus, under these conditions, FABP4 secreted by adipocytes might be modified and increase its affinity for palmitic acid, whose circulating levels increase in high-fat feeding. This evidence concerns the gene FABP4 and obesity due to melanocortin 4 receptor deficiency.