In 328 patients with de novo AML, when exons 2, 3, 4, and 11 of PTPN11, exons 8 and 9 of CBL, exons 1 and 2 of NRAS, and all NF1 exons were sequenced, NF1 gene abnormalities leading to changes in the Ras pathway were found in 2.1% of de novo patients [20] and poor prognosis was observed. This evidence concerns the gene NF1 and acute myeloid leukemia.