GJA1 and hepatocellular carcinoma: This discrepancy in Cx43 expression could be partially explained by the large amount of connective tissue in HCC specimens, by the various liver pathologies of HCC patients under study, and due to the appearance of isozymes (e.g., aldolase and γ-glutamyl transpeptidase) in human HCC, which have been described as the potential culprit for Cx43 expression level increase [149].