Published literature on new molecules for replacement treatment in hemophilia A and B has been retrieved by using PubMed search by using the name of the new molecules (i.e., “Fc fusion FVIII”, “FC fusion FIX”, “BAX855”, “GlycoPEGylated FVIII”, “GlycoPEGylated FIX”, “BAY 94-9027”, “rVIIISingleChain”, and “rIX-FP”). The gene discussed is F8; the disease is hemophilia A.