Tocagen is a clinical-stage, cancer-selective gene therapy company focused on developing product candidates designed to activate a patient's immune system against their own cancer. Co.'s cancer-selective gene therapy platform is built on Retroviral Replicating Vectors, which are designed to selectively deliver therapeutic genes into the DNA of cancer cells. Co.'s gene therapy approach is designed to fight cancer through immunotherapeutic mechanisms of action without the autoimmune toxicities commonly experienced with other immunotherapies.