DeltaRex-G, a tumor-targeted retrovector encoding a dominant-negative/cytocidal cyclin G1 (CCNG1 gene) inhibitor construct—has been tested in over 280 cancer patients worldwide in phase 1, phase 2 studies and compassionate use studies, demonstrating long term (>10 years) survivorship in patients with advanced cancers, including pancreatic cancer, osteosarcoma, malignant peripheral nerve sheath tumor, breast cancer, and B-cell lymphoma. Here, CCNG1 is linked to breast cancer.