In non-CNS malignancies, IDH mutations are identified in approximately 16% of acute myeloid leukemia (AML), myelodysplastic syndrome (DiNardo et al., 2015; Paschka et al., 2010; Mardis et al., 2009), 23% of intrahepatic cholangiocarcinoma (Borger et al., 2012), 56% of central/periosteal chondrosarcoma (Amary et al., 2011), colorectal carcinoma (Wood et al., 2007) and melanoma (Lopez et al., 2010; Shibata et al., 2011). The gene discussed is IDH2; the disease is acute myeloid leukemia.