On the other hand, although 5 mC enrichment was also increased at days 3 and 7 it was significantly blunted at day 7 compared with that at day 3 after SNL, suggesting that SNL may promote the hydroxylation of 5 mC to 5 hmC at the CpG sites in the bdnf promoter during the maintenance phases of neuropathic pain. This evidence concerns the gene BDNF and neuropathic pain.