Age, sex, irisin, educational level, duration of T2DM, HbA1C, FCP, waist circumference, BMI, waist-to-hip ratio, triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein, and HOMA-IR were entered as independent variables in the multiple step-wise linear regression analysis, with the MoCA score as the dependent variable. The gene discussed is FNDC5; the disease is type 2 diabetes mellitus.