CRTC2 is involved in regulating insulin sensitivity, endoplasmic reticulum stress (Wang et al. 2010b), endoplasmic reticulum stress(Wang et al. 2009), viral activation, and obesity(Murata et al. 2009), and CRTC2 plays an important role in regulating liver cell gluconeogenesis and maintaining the stability of fasting blood glucose. The gene discussed is CRTC2; the disease is obesity due to melanocortin 4 receptor deficiency.