Furthermore, through animal models, researchers are able to obtain a more comprehensive knowledge about vascular pathophysiology after stroke onset through different methods, such as gene regulation analyses18, erythropoietin- induced changes analyses19, biological factors (such as age)20, pathways21, stroke-related processes (such as neuronal injury)22, reactive astrocytes23, immune responses to dying neurons, glia and vessels24, cell survival and death, and tissue repair and functional recovery25. The gene discussed is EPO; the disease is Stroke.