Indeed, when equipped with a FVIII expression cassette driven by a reconstructed endothelial-specific F8 promoter, GP64-LV improved therapeutic efficacy in hemophilia A mice compared to VSV.G-LV, achieving reconstitution of therapeutically relevant FVIII activity up to the normal range and correction of the bleeding phenotype in hemophilia A mice. Here, F8 is linked to hemophilia.