CSE (cystathionine γ-lyase) is a key enzyme involved in the biosynthesis of endogenous hydrogen sulfide (H₂S), catalyzing the breakdown of cystathionine to produce H₂S. CSE consists of multiple functional domains and is primarily located in the cytoplasm and mitochondria. It plays an important role in regulating vasodilation, neurotransmission, and anti-inflammatory effects. The expression of CSE is tissue-specific, and mutations or dysregulation of its expression are associated with various diseases, including cardiovascular diseases, neurodegenerative diseases, and inflammation. The activity of CSE is regulated by multiple factors, affecting the physiological state and pathological processes of cells.