This chapter examines the commercial development of gene therapy and describes the creation of the American gene therapy industry and the different ways in which firms are developing the technology as both a clinical tool and a commodity. In particular, it focuses on the industry debate over how gene therapy can be used in clinical practice and how firms can make money out of this. A number of different conceptions for the application of gene therapy are described and related to the choices being made by firms for the design of the technology itself. Some reflections on the way in which gene therapy has been shaped in the process of commercialisation will be made.