In ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC), FAT1 and β-catenin expression are positively correlated with each other, and FAT1(−), β-catenin(−) or FAT1(−)/β-catenin(−) suggest worse disease-free survival55. Here, FAT1 is linked to ductal breast carcinoma in situ.