CXCL12 and non-proliferative diabetic retinopathy: Our results revealed that subjects carrying SDF-1 SNP rs2297630 GA (AOR: 2.962, 95% CI: 1.279-6.861, p = 0.011) and SDF-1 SNP rs2297630 GA + AA (AOR: 3.095, 95% CI: 1.394-6.872, p = 0.006) had significantly higher risk in the non-proliferative diabetic retinopathy (NPDR) groups than in the non-DR group.