Nitric oxide is a reactive free radical which acts as a biologic mediator in several processes, including neurotransmission and antimicrobial and antitumoral activities. Nitric oxide is synthesized from L-arginine by nitric oxide synthases. Variations in this gene are associated with susceptibility to coronary spasm. Alternative splicing and the use of alternative promoters results in multiple transcript variants.,NOS3,ECNOS,eNOS,Cancer,Signal Transduction,PI3K-Akt Signaling Pathway,Cell Biology & Developmental Biology,Endocrine & Metabolism,AMPK Signaling Pathway,Neuroscience,Cardiovascular,Angiogenesis,Blood,Hypoxia,NOS3