PNPLA2 and diabetes mellitus: The protein expression levels of PPARα, CD36, FABP3, fatty acid transporter 4 (FATP4) and carnitine acyltransferase 1 alpha (CPT1α), which are related to FFAs uptake and oxidation, were significantly upregulated in the hearts of the db/db mice compared with those of the db/m mice throughout the course of diabetes, whereas the expression of adipose triglyceride lipase (ATGL), which is an enzyme that promotes triglyceride hydrolysis, was significantly downregulated throughout the course of the disease (Figure 6A and B).