Genetic evidence indicated that TGF-alpha per a 1 SD increase promoted the occurrence of ketoacidosis (OR = 3.65, 95% CI = 2.95-4.52, P-value = 1.57e-32), neurological complications (OR = 1.89, 95% CI = 1.75-2.03, P-value = 5.13e-65), and ocular complications (OR=1.36, 95% CI =1.13-1.64, P-value= 0.0014) in type 2 diabetes, and there was no significant effect on nephrological complications and peripheral vascular complications. The gene discussed is TGFA; the disease is type 2 diabetes mellitus.