Although CXCL12 promoted the proliferation index in vitro, and AMD3100 suppressed the proliferation index in vitro, as well as the tumor size in vivo, our study did not disclose whether the CXCL12/CXCR4 axis is responsible for ESCC survival or apoptosis. The gene discussed is CXCR4; the disease is esophageal squamous cell carcinoma.