Nitrosylated proteins, DRP2, alpha-internexin, glutamate dehydrogenase 1, alpha-enolase, GFAP, MDH, ProSAAS precursor protein, proopiomelanocortin, proenkephalin, and septin are modified by S-nitrosyl-cysteine modification in the entorhinal cortex of AD in response to Aβ activation of glial cells surrounding SP, which conceivably leads to increased nitrosylation of GFAP, thereby contributing to the pathogenesis of AD. This evidence concerns the gene PENK and Alzheimer disease.