FABP4 and atrial fibrillation: The mRNA expressions of heart FABP (H-FABP/FABP3), adipocyte FABP (A-FABP/FABP4), and epidermal FABP (E-FABP/FABP5), brain FABP (B-FABP/FABP7) were significantly higher in AF, while the expression of liver FABP (L-FABP/FABP1) was significantly higher in IMF.