C4A and type 2 diabetes mellitus: Clinical variables including sAlb, fasting glucose, BUN, eGFR, CysC, UA, UTP, HbA1c, TG, Chol, HDLC, LDLC, Hb, phosphate, SBP, DBP, T2DM duration, sex, age, DR, family history, smoking status, pathological parameters of glomerular class, IFTA, interstitial inflammation, arteriolar hyalinosis, C1q, IgG, IgM, IgA, C3, C4 deposition in kidney biopsy samples, and the use of insulin, metformin, diuretics, CCB, ACEI, ARB, statins, and fibrates were used in the training of machine learning classifiers.