UBE2C and esophageal squamous cell carcinoma: Interestingly, UBE2C is nearly undetectable in normal tissues, at both the mRNA or protein levels, while increasing evidence has shown that UBE2C expression is up-regulated in several human cancers, such as esophageal squamous-cell carcinoma, gastric cancer, and non-small cell lung cancer and rectal cancer [4–7].