NOS1 (Nitric Oxide Synthase 1): NOS1 is an enzyme that produces nitric oxide (NO), a key signaling molecule in the body. It is essential for neurotransmission, regulation of vascular tone, and modulation of immune responses. In the nervous system, NOS1 supports neuronal communication and plasticity. Imbalances in NOS1 activity have been linked to neurological disorders, cardiovascular diseases, and inflammatory conditions.