Univariate Cox analysis revealed that SDF-1ɑ (CXCL12) expression, age, histologic grade, and clinical stage were associated with overall survival in renal cancer patients, and subsequent multivariate Cox analysis revealed that age, histologic grade, and clinical stage were independent risk factors for overall survival in renal cancer patients; moreover, high SDF-1ɑ (CXCL12) expression was a protective factor (Fig. 3A,B). This evidence concerns the gene CXCL12 and renal carcinoma.