AKT1 and cancer: This leads to a sustained proliferation signal within the cell, which is related to the migration and invasion of cancer cells.65,66 To assess the translation level of different signal proteins, we isolated total proteins from transfected A549 cells and conducted western blot analysis to investigate if the C14-PEI formulation can down-regulate KRAS pathways on the protein level, including the expression and activation of AKT and ERK.