CXCL12 and diabetes mellitus: The SDF-1 (c801G > A) variant was a significant predictor of DME in the multivariable regression model (OR: 2.48, 95% CL: 1.21–5.08; p = 0.01) after adjusting for the effect of risk factors for DME, such as the duration of DM, HbA1C level, hypertension, and microalbuminuria.