Since the very beginning the evident target of gene therapy were monogenic disease, though the number of applicated protocols in the treatment by oncologic processes has become much higher now. Several clinical studies, using viral vectors or direct transfer of plasmids containing sequences of human factor VIII, from which the central part (domain B) had been deleted gave satisfactory results concerning the transfer effectivity. On the other hand the amount of factor VIII produced in recipients was decreasing and was no more detectable after one year after administration of transfected fibroblasts.

        Key words: gene therapy, hemophilias