CLDN2 is highly expressed in human lung adenocarcinoma A549, RERF-LC–MS (JCRB0081, JCRB Cell Bank), and PC-3 (JCRB0077, JCRB Cell Bank) cells and involved in the regulation of cell proliferation, migration, and anticancer drug toxicity [17,25]. Here, CLDN2 is linked to lung adenocarcinoma.