These results suggest that LPS preconditioning alters transcription in cells, inhibits the production of TNF-α and other pro-inflammatory factors induced by NF-κB, enhances the level of IFN-β induced by IRF3, alleviates the secondary inflammation after cerebral ischemia injury, and produces ischemic tolerance (Figure 1B). This evidence concerns the gene NFKB1 and brain ischemia.