In a recent report by Dao et al., a CNL patient negative for the CSF3R mutation but still meeting strict WHO-defined criteria for CNL harbored a TET2 mutation along with potentially pathogenic mutations in PTPN11 (a non-receptor tyrosine kinase), TP53, DNMT3A, NF1, BCOR, BCORL1, PHF6, and RUNX1, as revealed by NGS150. The gene discussed is TET2; the disease is chronic neutrophilic leukemia.