In addition, specific cytokines, such as stromal cell-derived factor 1 (SDF-1) and angiopoietin-1, are produced by damaged tissues in the brains of adult animals to induce the activation of endogenous NSCs during disease states, such as cerebral ischemia, epilepsy, or trauma [41]. The gene discussed is CXCL12; the disease is Cerebral ischemia.