For instance, CNS-specific type 1 T helper (Th1) cells secrete interferon gamma (IFNγ) following ischemic stroke to recruit immune cells into the CNS [119] and activate cytotoxic CD8+ T cells, which exacerbate CNS damage by inducing apoptosis via caspase activation and Fas ligand signaling [120]. This evidence concerns the gene IFNG and ischemic stroke.