CLDN2 and colorectal carcinoma: While no significant change in primary tumor growth following caecal injection was observed in mice injected with Cldn2KO: WT, Cldn2KO: HA-WT, and Cldn2KO: HA-ΔPDZ HT-29 cells (Supplementary Fig. 3e, f), animals injected with CRC cells expressing Claudin-2 lacking the PDZ-binding domain exhibited an average 9.4-fold decrease in spontaneous liver-metastatic burden relative to mice injected with CRC cells expressing wild-type Claudin-2 (Supplementary Fig. 3e, f).