Since evidence has suggested that the level of Ubc9 protein was positively correlated with the degree of SUMOylation, we hypothesized that Ubc9 (the sole conjugase for SUMOs) target proteins have a role in the mediation of the neuroprotective effect against cerebral ischemia afforded by isoflurane preconditioning. This evidence concerns the gene UBE2I and brain ischemia.