H-Tyr-Phe-OH (L-Tyrosyl-L-phenylalanine) is an orally active inhibitor of Angiotensin converting enzyme (ACE), with an inhibiton rate of 48% at 50 μM. H-Tyr-Phe-OH can be used as an biomarker for differentiating benign thyroid nodules (BTN) from thyroid cancer (TC). H-Tyr-Phe-OH exhibits xanthine oxidase inhibition (uric acid lowering) activity and serves as regulator in IL-8 production in neutrophil-like cells[1][2][3][4].