TET2 and myelodysplastic syndrome: This is very similar to the aggressive myeloid leukemia reported in mice with inducible deletion of Tet2 and Tet3 in adult HSPCs that also have complete penetrance but a much shorter latency of 3 to 7 weeks (44) or to the phenotypes seen in Tet2-deficient mice that develop MDS and leukemia with 50% penetrance by 1 year of age (14, 43).