The frequency of CSF3R somatic mutations is reported to be of 80% in patients with CNL and, less commonly, these mutations are observed in atypical chronic myeloid leukemia (aCML, 40%), severe congenital neutropenia (SCN, 30%), chronic myelomonocytic leukemia (CMML, 5%) and acute myeloid leukemia (1.7% adult AML and 1.9% pediatric AML) [8–11]. This evidence concerns the gene CSF3R and severe congenital neutropenia.