Highly specific gain of function mutations in isocitrate dehydrogenase 1 or 2 (IDH1/2) were identified in patients with acute myeloid leukemia (AML) over a decade ago [4, 5], and have more recently been associated with T-cell leukemias [2, 3, 6, 7], especially EITP [8]. Here, IDH1 is linked to acute myeloid leukemia.