SETBP1 and chronic neutrophilic leukemia: Reports by several groups confirmed that the SETBP1 mutation is an important event in various classes of myeloid malignancies including CMML, CNL (Chronic Neutrophilic Leukemia), JMML, MDS, MDS/MPN (Myelodysplastic/Myeloproliferative neoplasms), and AML (Figure 3B).