Additionally, these Wnt-independent effects of APC in 4T07 mammary tumor cells are consistent with our previous characterization of APC-mediated regulation of epithelial polarization and tissue architecture and tumorigenesis in the mammary gland [5,6] that do not involve Wnt pathway hyperactivation, suggesting that Wnt-independent APC activities may be context- or tissue-specific. This evidence concerns the gene APC and breast cancer.