In order to further confirm that SOD2 suppression is due to hyperglycemia-induced H3K9me2 modification on the SOD2 promoter, the neurons were treated by either shRNA lentivirus for EHMT1, a specific histone methyltransferase that is responsible for H3K9me2 methylation (22), or an EHMT1-specific inhibitor BIX-01294, and the cells were harvested for further analysis (Fig. 2 H–K). This evidence concerns the gene PRDM9 and Hyperglycemia.