AIF1 and brain ischemia: Microglial cells are known to contribute substantially to the elevation of cytokine levels in the brain after focal cerebral ischemia (Lambertsen et al., 2012) and the lack of IBA1 microglial/leukocyte activation or recruitment in the ipsilateral hemisphere in BID-KO mice observed in the present study may be responsible for a lower levels of proinflammatory cytokines in BID-KO mice.