Human gene therapy: why draw a line?

Despite widespread agreement that it would be ethical to use somatic cell gene therapy to correct serious diseases, there is still uneasiness on the part of the public about this procedure. The basis for this concern lies less with the procedure's clinical risks than with fear that genetic engineering could lead to changes in human nature. Legitimate concerns about the potential for misuse of gene transfer technology justify drawing a moral line that includes corrective germline therapy but excludes enhancement interventions in both somatic and germline contexts.