Table 1 shows the frequencies of gene mutations in 3 different CMML cohorts in which comprehensive molecular analyses has been reported (9, 11, 32). Considering all molecular data reported mutations in TET2 (~60%), SRSF2 (~50%), ASXL1 (~40%) and RAS pathway (~30%) are most common (15) but no molecular aberration is specific of this entity, as they can be detected with different frequencies in other myeloid neoplasms (33). This evidence concerns the gene TET2 and chronic myelomonocytic leukemia.