TET2 and myelodysplastic syndrome: Chromosomal abnormalities, such as −7/7q‐, +8, 6q‐, 11q‐, i(7q), 11q‐, t(7;9), i(9q) and complex karyotypes (for MDS progression), double Ph chromosome, trisomy chromosome 8, trisomy chromosome 19, i(17q), t(3;21) and t(7;11) (for CML progression), as well as genetic mutations including TP53, DNMT3A, TET2, IDH1/2, EZH2 and ASXL1 in MDS are considered as progression‐related drivers 41, 42, 43.