LDN-27219 is a potent, reversible, slow-binding inhibitor of Tissue transglutaminase (TGase), which exhibits IC50 of 0.6 μM against human hTGase. It likely binds at the GTP-binding or regulatory site rather than the enzyme’s active site. It lowers blood pressure and improves endothelium-dependent vasodilation in resistance arteries in an age-dependent manner.