Namely, some authors showed higher Cx43 expression as a sign of progression to tumor (Brockmeyer et al., 2014), and higher Cx43 expression in tumors was regarded as a sign of worse prognosis, such as in case of esophageal SCC (Tanaka et al., 2016) and SqCC of oral cavity (Brockmeyer et al., 2014). This evidence concerns the gene GJA1 and esophageal squamous cell carcinoma.