PTK2 and neoplasm: It has been proposed that PTEN has double roles as a tumor suppressor: It may affect apoptosis and growth with its lipid phosphatase activity, which regulates levels of the PIP3 and Akt/PKB pathway, whereas it also participates in the regulation of cell migration, invasion and cytoskeletion by its protein tyrosine phosphatase activity targeting FAK and Shc [30].