Investigators from that study revealed that discrepant functional IFNL4 diplotypes non‐redundantly exerted differential impacts on molecular response (MR) in those ROPEG‐treated patients when assessed with changes in JAK2V617F mutant allele burden (AB)8 These data pave ways for potential application of precision medicine in optimizing patient management during IFN therapy for MPN. The gene discussed is IFNA1; the disease is myeloproliferative neoplasm.