HDAC5 and HDAC4 were markedly reduced in both cerebral ischemia/reperfusion injury and OGD model, and NADPH oxidase-reduced HDAC4 and HDAC5 accelerates cerebral ischemia injury via increasing the expression and release of high mobility group box-1 protein (HMGB1) [99]. The gene discussed is FMO5; the disease is brain ischemia.