An in vitro study by Huang et al (88) has shown that overexpression of HIF1α inactivates microglia during re-exposure to hypoxia and reduces their activity and could, therefore, be a novel method of achieving neuroprotection after ischemic stroke or brain ischemia by diminishing the possibility of occurrence of A1 reactive astrocytosis. This evidence concerns the gene HIF1A and brain ischemia.