As the expression of NOS2 is controlled by NF-κB [35], the decrease in NOS2 in triptolide-treated APP/PS1 mice most likely resulted from the inhibition of NF-κB by triptolide via its action on XPB/TFIIH, counteracting the increase of neuroinflammation in these AD mice. Here, NOS2 is linked to Alzheimer disease.