Univariable logistic regression analysis demonstrated significant associations between DKD risk and the following variables: SBP, BUN, HCO3, eGFR, creatinine, UA, cystatin C, duration of T2DM, staging of diabetic retinopathy (DR), number of cotton wool spots, microaneurysms, FD, MVD, MVeD, VD, and VD within 3-mm and 5-mm FAZ (all P < 0.05). The gene discussed is CST3; the disease is diabetic kidney disease.