AKT1 and neoplasm: For example, the target enzymes of the most widely used tyrosine kinase inhibitors are usually responsible for activating several intracellular molecular pathways involved in tumor cell proliferation, such as phosphatidylinositol 3-kinase (PI3K), serine/threonine-specific protein kinase (Akt), and mammalian target of rapamycin (mTOR).