Wnt pathway components, including Axin, β-catenin and Adenomatous polyposis coli (APC), are frequently mutated in colorectal adenocarcinoma but this is uncommon in breast cancer samples (Zhan et al., 2017), where β-catenin activation is not driven by β-catenin gene (CTNNB1) mutations (Geyer et al., 2011). Here, APC is linked to breast cancer.