Accumulation of nuclear or mitochondrial DNA of dying cancer cells in extracellular spaces or the cytosol as a result of responding to chemotherapy elicits immune signaling via Toll-like receptor 9 (TLR9), TLR3, and GMP-AMP synthase (CGAS) that eventually results in the production of type I interferons (IFNs) (70, 71). The gene discussed is TLR9; the disease is cancer.