Our data indicate that CSF3R mutations are not exclusively present in CNL (80–90% of cases) or aCML (5–10%) but are detectable in about 3% of AML patients and 7% of CMML patients [14, 15, 18, 31, 32]. This evidence concerns the gene CSF3R and atypical chronic myeloid leukemia, BCR-ABL1 negative.