XBP1 and obesity due to melanocortin 4 receptor deficiency: Consistent with our hypothesis we found that CST treatment exhibits ER stress lowering effects: (i) decrease of obesity-induced ER dilation (Fig. 8A-C) decreased mRNA abundance for ATF6 (Fig. 8D and ATF4 genes (Fig. 8E, (iii) decreased abundance of (Fig. 8F) (iv) spliced Xbp1 mRNA decreased phosphorylation of PERK (Fig. 8G & I), eIF2α (Fig. 8G & J), and IRE1α (Fig. 8G & H).