Nitric oxide synthase (NOS) is an enzyme responsible for producing nitric oxide (NO), a crucial signaling molecule in the body. There are three main types of NOS: neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). Each type is found in different tissues and plays specific roles in regulating various physiological processes, such as blood flow, neurotransmission, and immune responses. Nitric oxide acts as a vasodilator, helping to relax blood vessels and improve circulation. It also plays a role in neurotransmission in the nervous system and can influence immune responses by modulating the activity of immune cells. The proper functioning of nitric oxide synthase is essential for maintaining cardiovascular health and