These include DNMT3A and TET2, commonly deleted in myelodysplastic syndrome, myeloproliferative disorder, and acute myeloid leukemia [34,35]; PRAME, DLEU7, DLEU1, and DLEU2, frequently deleted in chronic lymphocytic leukemia, the most common leukemia in older adults [36–39]; L3MBTL1, a putative tumor suppressor in myeloid disorders harboring del(20q12) deletions [40]; and RB1, a well-studied tumor suppressor mutated in many leukemias [41]. The gene discussed is TET2; the disease is leukemia.