4-CPA, or 4-chlorophenylalanine, is an amino acid derivative characterized by the presence of a chlorine atom on the phenyl group. It is often studied in biochemical and pharmacological contexts due to its potential effects on neurotransmitter systems and protein synthesis. 4-CPA can act as an inhibitor of certain enzymes, making it useful in research related to metabolic pathways and neurobiology. Its applications may extend to understanding various physiological processes and developing therapeutic agents.