PTEN and colorectal carcinoma: In the transduction of proliferative and antiapoptotic signals in CRC cells, the signaling cascades RAS/RAF/MEK/ERK (extracellular signal regulated kinase) and PTEN (phosphatase and tensin homolog)/PI3K (phosphatidylinositol 3-kinase)/AKT/mTOR play pivotal roles [5, 6].