Our results show that PLEKHA7 protein expression and accumulation at sites of cell-cell contact confirm its zonular localization in human normal and cancer epithelial cells, decreases with increasing grade in ductal breast carcinomas, and is lost in lobular carcinomas, in a pattern that distinguishes it from other markers of both ZA and TJ. Here, PLEKHA7 is linked to breast ductal adenocarcinoma.