F9 and hemophilia A: Two congenital types of hemophilia are the most common, hemophilia A (HA) (1 in 5000 male births), in which there is a lack or deficiency of factor VIII (FVIII), and hemophilia B (HB) (1 in 30,000 births), accompanied by a lack or deficiency of factor IX (FIX) [1,2].