Hemophilia A is a chronic bleeding disorder resulting from a deficiency in coagulation factor VIII (F8). Current treatment strategies rely on frequent F8 replacement therapy, which is limited by its short half-life, high cost, and the risk of inhibitor development. Gene therapy using adeno-associated virus serotype 8 (AAV8) has emerged as a promising modality, offering liver-targeted, long-term transgene expression. This article recently published in Blood Science investigates whether targeted deletions adjacent to the furin cleavage site of F8 can enhance the therapeutic efficacy and safety of AAV8-delivered BDDF8 constructs in a murine model of hemophilia A.