CXCR4 and esophageal squamous cell carcinoma: Gockel et al. validated CXCR4 expression in 94.1% of resectable ESCC patients (54.9% weak expression vs. 45.1% strong expression) and 89.1% resectable EAC patients (71.7% weak expression vs. 29.3% strong expression), strong CXCR4 expression was supposed to be relevant to poor prognosis in both subtypes [198].