 In initial proof-of-concept experiments, BOEC lines will be established from the peripheral blood of normal individuals and research subjects with Von Willebrand disease. Following culture and phenotypic characterization, they will be transduced with a lentivirus gene transfer vector expressing a reporter gene or wild-type Von Willebrand factor. After demonstrating successful transduction, the next step will be to write an animal protocol that will introduce the modified cells into immunocompromised mice and monitor the mice for stable implantation. 