In the subgroup analyses of ethnicity, the meta-analysis results indicated a strong association between the SDF-1 rs1801157 polymorphism and cancer susceptibility among Asians (AA + AG vs. GG, OR: 1.63, 95% CI: 1.34–1.98, P < 0.001) and a weak association in Caucasians (AG vs. GG, OR: 1.10, 95% CI: 1.00–1.21, P = 0.05), but no association in mixed populations using different genetic models (Table 3). The gene discussed is CXCL12; the disease is cancer.