USP25 and ischemic stroke: Ischemic stroke induces the migration, proliferation, and activation of microglia, which are brain‐resident immune cells, in the infarcted area and activated microglia contribute to the establishment of an inflammatory milieu that is detrimental to neurons.[17] We found that, after MCAO, USP25−/− mice had significantly more microglia in the infarcted penumbra than WT mice (Figure 2C,D).