Some studies have reported that impaired activity of NOS is associated with neurodegenerative diseases such as Alzheimer's disease, and NOS inhibitors disrupt memory consolidation and LTP formation, whereas L‐arginine, as a NO precursor, improves memory formation (Asiimwe, Yeo, Kim, Jung, & Jeong, 2016). This evidence concerns the gene NOS2 and early-onset autosomal dominant Alzheimer disease.