CLDN2 and breast neoplasm: As expected from the previous study, Kaplan-Meier analysis of 206 human metastatic breast cancer tumors revealed that high expression of Claudin-2 in primary breast tumors was associated with shorter BCSS (P = 0.001), an increased risk of developing distant metastases (P = 0.028), and liver-specific metastases (P = 0.027), although only a trend was observed with LuMFS (P = 0.088) (Fig. 6A).