CCN2 and esophageal squamous cell carcinoma: Overexpression of CTGF has been found in various cancers, including pancreatic cancer, prostate cancers, and gliomas, acute lymphoblastic leukemias, esophageal squamous cell carcinomas [13–17], and is implicated in tumor progression by regulating proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) of cancer cells [18].