Following cerebral ischemia/ reperfusion, mice exposed to nPM demonstrated significantly higher complement C5 densities in the ischemic core [1378.18 ±127.97 (n = 3)] when compared to mice exposed to filtered air [761.29 ±82.93 (n = 3); p<0.01; Fig 4]. The gene discussed is C5; the disease is brain ischemia.