In the past three years, the FDA has approved two mutant IDH (mutIDH) inhibitors for relapsed or refractory AML harboring IDH mutation, namely enasidenib (AG-221)—which is a first-in-class oral selective inhibitor of the mutIDH2 enzyme—and ivosidenib (AG-120)-targeting mutIDH1 [93]. The gene discussed is IDH2; the disease is acute myeloid leukemia.