Over the past few years, a large number of mutations in genes encoding epigenetic regulators (TET2, ASXL1, EZH2, UTX, IDH1, IDH2, and DNMT3A), splicing factors (SF3B1, SRSF2, ZRSF2, and U2AF1), and signaling molecules (NRAS, KRAS, CBL, JAK2, and FLT3) have been identified in clonal cells in CMML [12]. This evidence concerns the gene TET2 and chronic myelomonocytic leukemia.