CREB3L3 and obesity due to melanocortin 4 receptor deficiency: Similarly, this specific downregulation of CREB3L3 was observed in the iWAT of a genetic model of obesity (ob/ob) (Fig. 1b), and was also seen at the protein level, as evidenced by the reduced abundance of CREB3L3 in the iWAT of C57BL/6J mice following high-fat feeding (Fig. 1d).