MARK2 and neoplasm: S3 Fig. [23] represents an abstract model of HER2 overexpressed breast cancer where PHLPP isoforms are a pair of protein phosphatases, PHLPP1 and PHLPP2, which are important regulators of AKT serine-threonine kinases (AKT1, AKT2, AKT3) and conventional protein kinase C (PKC) isoforms. PHLPP may act as a tumor suppressor in several types of cancer due to its ability to block growth factor-induced signaling in cancer cells [24]. PHLPP dephosphorylates SER473 (the hydrophobic motif) in AKT, thus partially inactivating the kinase [25].