CLDN1 and renal carcinoma: In this study, we have shown that the expression of claudin-6 was observed in both membrane and cytoplasm/membrane in the FA and IDC of the breast, similar to previous studies on the claudin-6 in atypical teratoid/rhabdoid tumors [26], claudin-1, and claudin-7 in colonic and renal carcinomas, respectively [27,28].