CXCL12 and carcinoma of esophagus: For the further study about the effect of SDF-1–CXCR4 axis on the invasion and metastasis of ESCC and provide the new target spot to remedy ESCC, the siRNA for CXCR4 were designed to research the effects of CXCR4 on proliferation and invasion of esophageal carcinoma.