APC and adenoma: The study of APC-deleted mice models of colon carcinogenesis suggested that intestinal stem cells (e.g., LGR5+ cells) may act as the cells of origin for cancer when APC is deleted, or a constitutive β-actin is expressed; however, the induction of activation WNT signaling in differentiated cells induces de-differentiation and adenoma formation, but this process requires additional mutational oncogenic events (reviewed in [273]).