The positive outcome on the joint function in an adult with late prophylaxis treatment has been confirmed even after 3 years of prophylaxis treatment, as reported in the prospective randomised trial of Secondary Prophylaxis with recombinant FVIII Therapy in Severe Hemophilia A Adult and/or Adolescent Subjects Compared to that of Episodic Treatment (SPINART) (6). This evidence concerns the gene F8 and hemophilia A.