A receptor for osteopontin, the integrin αvβ3, is also up-regulated in reactive astrocytes that localize to the peri-infarct area 5 days after ischemia and to an osteopontin-rich, glial barrier 15 days post-ischemia, suggesting that αvβ3 and its extracellular ligands are involved in reactive astrogliosis46. The gene discussed is SPP1; the disease is ischemia.