Prostate-specific membrane antigen (PSMA) also known as Folate hydrolase 1 (FOLH1), Folylpoly-gamma-glutamate carboxypeptidase (FGCP), Glutamate carboxypeptidase 2 (GCP2), N-acetylated-alpha-linked acidic dipeptidase I (NAALAD1), is a type II membrane glycoprotein that is expressed in prostate tissue and to a lesser extent in the peripheral and central nervous system, small intestinal, and salivary gland tissues. PSMA has both folate hydrolase and N-acetylated-alpha-linked-acidic dipeptidase (NAALADase) activity and has a preference for tri-alpha-glutamate peptides. The catalytic activity of PSMA involves the release of unsubstituted C-terminal glutamyl residues, typically from Ac-Asp-Glu or folylpoly-gamma-glutamates. PSMA is used as a diagnostic and prognostic indicator of prostate cancer, and as a possible marker for various neurological disorders such as schizophrenia, Alzheimer’s disease, and Huntington’s disease.