CST1 and breast carcinoma: The upregulation of CST1 expression is closely associated with poor prognosis in breast cancer patients (Dai et al., 2017) and colon cancer (Li et al., 2017b; Jiang et al., 2018), consistent with our results verifying the expression of CST1 in esophageal cancer tissues and cell lines by immunohistochemistry (IHC) and western blotting.