MARK2 and neoplasm: The serine/threonine kinase Akt, also called protein kinase B or PKB, is the most important downstream effector of PI3K and has been proved to play an important role in tumorigenesis and tumor growth49, which can be due to that Akt protects tumor cells from death through phosphorylation and inactivation of downstream substrates27, 29, such as antiapoptotic proteins Bcl-2, proapoptotic proteins Bax and Bad57, ASK-1, cyclin-dependent kinase p21 and Cyclin D126, P27, GSK-3, and so on (Fig. 8a)29.