Multivariate forward stepwise linear regression analysis revealed that body fat mass (adjusted R2 change = 0.218; P=0.008) and log-TG (adjusted R2 change = 0.036; P < 0.001) positively correlated, whereas eGFR (adjusted R2 change = 0.033; P=0.013) negatively correlated with serum FGF21 levels in T2DM patients. The gene discussed is FGF21; the disease is type 2 diabetes mellitus.