PITX1 and neoplasm: Specifically, Pituitary homeobox 1 (PITX1) exerts a tumor suppressive effect in hepatocarcinogenesis through regulation of Ras guanosine triphosphatase-activating protein (p120RasGAP) expression levels, but PTPN1 attenuates the protein stability of PITX by directly dephosphorylating PITX1 at residues Y160, Y175 and Y179 (144).