In these experiments, we found that fedratinib downregulates expression of several surface antigens, including CD105, CD117, CD123, and CD133, and less effectively CD26 and CD97 in MPN NSC, suggesting that the JAK2‐STAT5 pathway is involved in expression of these antigens on MPN stem cells. This evidence concerns the gene DPP4 and myeloproliferative neoplasm.