Of 2926 cases with a myeloid NGS test performed, 79 patients with DNMT3A mutant MNs were identified, including 40 (51%) AML, 28 (35%) MDS, 3 (4%) MDS/MPN (myelodysplastic syndrome/myeloproliferative neoplasm), and 8 (10%) MPN. The gene discussed is DNMT3A; the disease is myeloproliferative neoplasm.