CLDN1 and neoplasm: This analysis led us to the identification of TACSTD2 as one of the most likely candidates that might affect HCV entry because: (i) it was the second most downregulated gene within the tumor tissue; (ii) it showed a strong positive correlation with HCV RNA levels; and (iii) it had previously been linked with the regulation of CLDN1 localization and function in corneal epithelial cells [21].