XBP1 and obesity due to melanocortin 4 receptor deficiency: To investigate whether the STF amelioration of insulin resistance and obesity reflects on its inhibition of IRE1α activity in adipose tissue, we examined the status of IRE1α-mediated Xbp1 mRNA splicing in WAT from STF-treated DIO mice and observed that as assessed by RT-PCR followed by electrophoretic separation, the level of spliced Xbp1 (XBP1s) mRNA was significantly reduced in both eWAT (Fig. 1G–G’) and iWAT (Fig. S1E–E’) from STF-treated animals relative to vehicle group.