Following the outbreak in the 1980s of blood-borne infectious diseases (particularly HIV and HBV/HCV infections) in hemophilia patients who received pd-FVIII products that had not been subjected to virus inactivation or removal treatments, the manufacturers of those products introduced virus sterilization steps into their production methods and increased the purity of the preparations via DNA genetic engineering, thus greatly improving safety. This evidence concerns the gene F8 and hemophilia.