Taken together, these data demonstrate B-VEC-mediated COL7A1 gene delivery, expression, and correct ultrastructural localization of functional, full-length C7 (inclusive of both NC1 and NC2) in RDEB mouse and primary human RDEB skin xenograft models, both of which closely recapitulate the RDEB skin phenotype. The gene discussed is COL18A1; the disease is recessive dystrophic epidermolysis bullosa.