Provisional diagnostic algorithm for neutrophilia and genetically informed treatment options. †FISH probes for myeloid-associated cytogenetic abnormalities can be used to complement standard karyotype analysis to establish the presence of a clonal myeloid disorder. Cytogenetic/FISH or molecular evaluation of rearranged PDGFRA/B, and FGFR1 should also be considered if eosinophilia is present. ‡Testing for JAK2 V617F, infrequently identified in CNL or atypical CML, should also be considered. The list of relevant mutations, including molecular abnormalities in complementary signaling pathways to CSF3R and SETBP1, may expand over time. *For patients who are CSF3R-mutation negative, use of a JAK inhibitor (particularly if JAK2 V617F positive) or SRC kinase inhibitor could be considered since mutations in the same or related signaling pathways may be present.