CXCR4 and esophageal squamous cell carcinoma: We previously found that CXCR4 rs6430612 polymorphism is a telomere length-related SNP contributing to GCA risk, with the T allele as a protective allele 40.CXCR4 is a chemokine receptor whose expression was significantly correlated with invasion, angiogenesis, metastasis, and prognosis of ESCC 41-43.