Molecular abnormalities are detected in about 90 % of patients with CMML [2, 3] including TET2 in 50–60 %, SRFS2 in 40–50 %, ASXL1 in 40–50 % and SETBP1 in 5–10 % [2, 4]. This evidence concerns the gene TET2 and chronic myelomonocytic leukemia.