PTPN11 and colonic neoplasm: Genetic mutations in PTPN11 exon 3(encoding the N-SH2 domain), exon 4(encoding the C-SH2 domain), Exons 7, 8 and 12(encoding the PTP domain) have been identified in Noonan syndrome, juvenile myelomonocytic leukemia, LEOPARD syndrome, lung cancer, liver cancer and colon cancer [29].