F8 and hemophilia A: In the last four decades, numerous efforts and remarkable advances have been made in the treatment of haemophilia A. Previous studies have shown that Adeno‐associated virus (AAV) vectors injected into the liver or muscle can produce FVIII at a therapeutic level and ameliorate disease symptoms in mouse and dog animal models of haemophilia A.6, 7Encouraged by these findings, researchers designing clinical trials have focused on in vivo clotting factor gene transfer to cure haemophilia using AAV delivery.