Globally, in s-AMLs, IDH1 and IDH2 mutations are observed at a frequency similar to that observed in de novo-AMLs; however, the majority of IDH1- and IDH2-mutated s-AMLs cluster within the subgroup characterized by the presence of secondary-type mutations; IDH1 and IDH2 mutations were absent in the subgroup of s-AMLs displaying TP53 mutations and in part were present in the subgroup of s-AMLs characterized by a de novo-like AML mutational pattern [63]. The gene discussed is IDH2; the disease is acute myeloid leukemia.