Gene therapy is a promising medical technology that has the ability to treat inherited diseases. However, efficient and economical large-scale production of vectors is necessary to meet the potential patient demand. Several approaches have been evaluated for the mass production of retroviral vectors, including fixed-bed bioreactors, suspension cultures, and microcarrier cultures. In this article, we report on the use of a Cytopilot fluidized-bed bioreactor for the production of retroviral vectors from the human packaging cell line TEFLYRD…