IDH2 and acute myeloid leukemia: Intriguingly, 4 of these non-synonymous variations, found in 4 different patients, were previously associated in the literature with AML: NRAS p.G13R (NM_002524) identified in heterozygosis with an allelic frequency (AF) of 34%; KRAS p.Q61H (NM_001369786; AF = 6%); KRAS p.G13D (NM_001369786; AF = 12%); and IDH2 p.R140Q (NM_002168; AF = 6%).