In diabetic patients, multivariate unconditional logistic regression was performed with DFU as the dependent variable and sex, age, duration of diabetes, regular smoking, long-term alcohol consumption, mean sunshine duration per day in the recent 3 months, SBP, DBP, FPG, HbA1c, TG, TCH, LDL-C, HDL-C, eGFR, ALB, Hb, TcPO2, ABI, CRP, WBC, ESR, serum 25(OH)VD level, P-IL-6 level and P-IL-10 level as independent variables, respectively. The gene discussed is GSTM1; the disease is diabetes mellitus.