CLDN1 and pancreatic adenocarcinoma: Several studies have reported an increased expression of CLDN1 in human lung adenocarcinoma, linking it to anthracycline (including DOX) resistance and decreased penetration [90,91], and in several other tumors, including colon, hepatocellular, and pancreatic adenocarcinoma, as well as in breast cancer [92,93,94,95].