Recurrent IDH1/2 mutations reported in AML are somatic missense mutations affecting highly conserved arginine residues at codon 132 in exon 4 of IDH1 (IDH1R132) and at codons 140 and 172 in exon 4 of IDH2 (IDH2R140 and IDH2R172) [17,36]. The gene discussed is IDH1; the disease is acute myeloid leukemia.