By immunohistochemical staining of 47 pairs of ESCC tissues and paracancerous tissues, CST1 protein was shown aberrant expression evidented by the positive rate up to 68.1% in cancerous tissues significantly higher than that of paired paracancerous tissues (Table 1, Fig 2A and 2B), and correlated with tumor stages; in addition, by RT-qPCR of 20 pairs of ESCC tissues and paracancerous tissues, CST1 mRNA levels in ESCC tissues were also shown significantly upregulated (Fig 2C). This evidence concerns the gene CST1 and neoplasm.