APC and neoplasm: More likely, given that MMTV-PyMT mammary carcinogenesis is β-catenin independent [55] and that β-catenin can regulate CD24 expression [54], it is tempting to speculate that CD24 might be functionally relevant during APC/β-catenin-dependent tumorigenesis, which might explain why some tumor types appear to be more sensitive to CD24 deficiency than others.