GSNOR (S-Nitrosoglutathione Reductase) is a crucial enzyme responsible for regulating intracellular S-nitrosylation levels, affecting protein function and signal transduction. It is expressed in various tissues, particularly enriched in the heart, lungs, and brain, participating in nitric oxide signaling pathways that influence vasodilation, neurotransmission, and cell death. The gene expression of GSNOR is strictly regulated, and abnormalities in its activity or expression levels are closely associated with conditions such as asthma, cardiovascular diseases, and neurodegenerative diseases. Deficiency or dysfunction of GSNOR can lead to dysregulation of cellular responses to oxidative stress.