Is cancer gene therapy an empty suit?

Gene therapy as a treatment for cancer is regarded as high in promise, but low in delivery, a deficiency that has become more obvious with ever-increasing reports of the successful correction of monogenic disorders by this approach. We review the commercial and scientific obstacles that have led to these delays and describe how they are progressively being overcome. Recent and striking successes and correspondingly increased commercial involvement suggest that gene transfer could finally become a powerful method for development of safe and effective cancer therapeutic drugs.