PSMA (prostate-specific membrane antigen) is a transmembrane enzyme primarily composed of a large extracellular domain, a transmembrane region, and an intracellular tail. It is mainly located on the membrane surface of prostate epithelial cells, as well as in certain other tissues and tumor cells. PSMA is involved in the cleavage of peptides and nucleotides, influencing cell signaling and nutrient absorption. In prostate cancer, PSMA is significantly upregulated, making it an important target for diagnosis and treatment. The gene expression of PSMA is tissue-specific, and mutations or dysregulation are associated with the development and progression of prostate cancer.