AKT1 and colorectal carcinoma: In this study, we demonstrate that in CRC cells, irinotecan strongly activates the PI3K/AKT/mTOR and MAPK pathways, at least in part via the IR, and that the combination of irinotecan with both a PI3K inhibitor and a MEK inhibitor induces a synergistic effect in terms of cytotoxic activity (Fig. 7).