Subjects with moderate haemophilia A exhibit between 1 and 5% endogenous FVIII activity [i.e., 1 –5 IU/dL], and subjects with mild haemophilia A exhibit between 5 and 40% endogenous FVIII activity [i.e., 5–40 IU/dL] [2]. The gene discussed is F8; the disease is hemophilia A.