PTEN and colorectal carcinoma: By examination of the morphogenetic transition zones in a large number of primary CRC tumors, we uncovered a localized CSC-like transition zone of multifocal alternating quiescent/proliferative adenomatous epithelium affecting multiple stem cell and cell cycle markers, including Ki-67, ALDH1, β-catenin, CD44, EZH2, MGMT, MYC, PTEN, P53, and SMAD4.