In high throughput genome‐wide studies, somatic deletion and loss of function TET2 mutations are detected in 7–23% of acute myeloid leukemia (AML), 10%–20% of myelodysplastic syndrome (MDS)/myeloproliferative neoplasms (MPN), and 40%–50% chronic myelogenous leukemia patients [2, 4–6]. The gene discussed is TET2; the disease is acute myeloid leukemia.