H-Tyr-Phe-OH(L-Tyrosyl-L-phenylalanine) is a dipeptide/polypeptide composed of tyrosine and phenylalanine that inhibits the activity of the angiotensin-converting enzyme (ACE) and has oral activity. It can be used as a biomarker for the study of thyroid nodules and also exhibits xanthine oxidase inhibitory (uric acid lowering) activity and acts as a regulator of IL-8 production by neutrophil-like cells.