PTPN11 and leukemia: SHP-2 was earlier reported as proto-oncogene.46, 47, 48 Over the past few years, a number of disease-associated SHP-2 mutations have been identified in Noonan syndrome, leukemias and other malignancies.46, 48, 49 Bard-Chapeau et al.50 reported that SHP-2 has a tumor-suppressor function in liver.