According to the recommendations of the International Society of Thrombosis and Hemostasis (ISTH), the PK of new clotting extended half-life (EHL) recombinant FVIII (rFVIII) concentrates should be evaluated in comparative studies against standard half-life (SHL) rFVIII concentrates, in small-medium size populations of 20–40 severe hemophilia A (HA) patients [14,15]. The gene discussed is F8; the disease is hemophilia A.