Using a db/db mouse (db/db-m) as a type 2 diabetic model and db/db-ChAT-tgm, Saw et al. demonstrated that although GLUT4 was significantly decreased in the heart of db/db mice in a progressive stage of DM, in db/db-ChAT-tgm, the expression of type 2 muscarinic ACh receptors and its downstream targets, HIF-1α and GLUT4, in the heart were increased compared with those in db/db-m (34). This evidence concerns the gene CHAT and diabetes mellitus.