The first of these examined ruxolitinib in CNL and aCML patients (NCT02092324) and showed a significantly enhanced response rate in patients with mutant compared to wild-type CSF3R (54% vs. 9%; n = 25) and improvements in WBC parameters and spleen size (n = 29) [70]. The gene discussed is CSF3R; the disease is atypical chronic myeloid leukemia, BCR-ABL1 negative.