Because the patient did not meet the criteria for other MPN disorders, CNL was diagnosed according to the WHO classification criteria, classified as High-risk CNL based on the operational risk model predicting long-term survival in CNL, which was developed from data captured from 19 molecularly annotated, patients with CSF3R-mutated CNL from the Mayo Clinic [1]. The gene discussed is CSF3R; the disease is chronic neutrophilic leukemia.