CTNNB1 and invasive ductal breast carcinoma: Alterations in the genes encoding APC and CTNNB1 are frequently mutated in not only lethal mCRPC but also ductal adenocarcinoma and upregulate Wnt‐β‐catenin pathway signaling6, 7, 8, 9, 30 Table 2 shows that APC alterations were found in four cases (33.3%), which is slightly more frequent than that in other studies on ductal adenocarcinoma (10%–27%)6, 7, 8, 9 and significantly more frequent than that in the SU2C‐PCF set (9%)18 in our cohort.