IRS1 and neoplasm: Additionally, it has been reported that PTEN can directly dephosphorylate residues on itself and several other protein substrates, including phosphoprotein focal adhesion kinase 1 (FAK), Shc, cAMP-responsive element-binding protein 1 (CREB1), insulin receptor substrate 1 IRS1, Dishevelled (DVL), and others to exert its tumor suppressive functions [[22], [23], [24], [25], [26], [27]].