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). This evidence concerns the gene PTPN1 and neoplasm.