CSF3R and chronic neutrophilic leukemia: Similar mutations have also been identified in chronic neutrophilic leukemia (CNL), atypical chronic myelogenous leukemia (aCML) and chronic myelomonocytic leukemia (CMML) patients (9, 11–14), although these are usually co-incident with alternative constitutively-activating G-CSFR mutations (15).