Gene therapy as a treatment for cancer is at a critical point. Exciting new developments, coupled with results from the first generation of studies have led to design and testing of new approaches. The Third Edition of Gene Therapy of Cancer is a comprehensive assessment of the field including suicide gene therapy, oncogene and suppressor gene targeting, and drug resistance gene therapy. Researchers at all levels will find this book e instructive. Cancer gene therapy is evolving rapidly, testing new concepts, targets and pathways, evoking new technologies, and passing new regulatory hurdles. Its essence, however, has not changed: the hope and challenges of returning altered genes to normal, using targeted gene expression to alter the function of tumor and microenvironment, and in some cases normal cells, and delivering functionally important genes to specific cell types to increase sensitivity to killing or to protect normal cells from cancer therapies. Gene therapy for cancer can form a continuum from gene repair through the use of molecularly modified cells; the use of viral and non-viral vector-based gene delivery; the use of viral and gene-based vaccines; and development of new gene-based therapeutics. The unique mechanistically chosen vector platforms are at the heart of this technology because they allow direct and selective cell death and transient to sustained delivery of vaccine molecules or molecules that affect the microenvironment, vasculature, or immune response.