Among the cases with no recurrent cytogenetic abnormalities according to the 2008 WHO Classification, 92.3% (48/52) of AML, not otherwise specified (AML-NOS) and 81.4% (35/43) of AML-MRC had at least one mutations in the 19 genes examined (Table 4).NRAS mutation was more frequent in AML-MRC (16.3% vs. 3.8%, P=.074), whereas TET2 mutation was less frequent in AML-MRC than AML-NOS (2.3% vs. 19.2%, P=.011). The gene discussed is NRAS; the disease is acute myeloid leukemia.