Importantly, as a novel regulator of metabolic homeostasis (Lee et al., 2008; Zhou et al., 2011; Wu et al., 2014), the proposed XBP1 regulation of VEGF also broadens our knowledge on the pathologies of metabolic syndrome and sheds light on the intervention of diabetes mellitus and obesity‐related metabolic diseases. The gene discussed is VEGFA; the disease is obesity due to melanocortin 4 receptor deficiency.