In total, 42 healthy volunteers (Group A); 68 individuals with diabetes (Group B) who exhibited microalbuminuria, defined by a urinary albumin-to-creatinine ratio (ACR)< 30 mg/g and an estimated glomerular filtration rate (eGFR) within the range of 60–120 mL/min/1.73m2; and 53 patients with diabetic nephropathy (Group C) were included in the study. The gene discussed is ALB; the disease is diabetic kidney disease.