Used in the synthesis of radiolabeled compounds for medical imaging, particularly in positron emission tomography (PET) scans. Its structure allows incorporation into peptides and proteins to track biological pathways and receptor binding in cancer and neurological research. The iodine atom facilitates labeling with radioactive isotopes like iodine-124 or iodine-131, enabling both imaging and targeted radiotherapy. Also employed as a building block in developing enzyme inhibitors and bioactive molecules in medicinal chemistry.