Down-regulated CK18 protein seemed to promote cell migration [49] and progression of breast [34], nasopharyngeal [44] as well as colon cancers [50], though up-regulated CK18 protein was shown to correlate with poor differentiation, advanced stage, metastasis and recurrence in lung [51], renal cell [52], oral cavity [53], and esophageal squamous cell carcinomas [54]. The gene discussed is KRT18; the disease is esophageal squamous cell carcinoma.