FNDC5 and brain ischemia: In the mouse cerebral ischemia model induced by middle cerebral artery occlusion, the level of irisin was negatively correlated with the cerebral infarction volume and brain function injury score, whereas in those treated with r-irisin, the cerebral infarction volume, nerve function injury, and brain edema of the mice were significantly improved, which were related with phosphorylation of ERK1/2-Akt–mediated inflammation (39).