When platelet-FVIII expression was introduced into hemophilia A rats after transplantation of 2bF8 genetically manipulated bone marrow cells from 2bF8 transgenic rats, the spontaneous bleeding phenotype was rescued with no inhibitor development even though animals were continuously exposed to platelet-FVIII after bone marrow transplantation (26). The gene discussed is F8; the disease is hemophilia A.