NOS2 and Alzheimer disease: In the PC12 cell model of AD, 12 selected genes more frequently referred to AD by previous studies among all the genes identified by network pharmacology, DYRK1A, FOXO1, NOS2, NGF, NQO1, NOTCH3, BCL6, HMGB1, KEAP1, RORA1, STAT3, and CXCL16, were detected by the qRT-PCR with or without 80 μM quercetin.