Echistatin TFA, the smallest active RGD protein belonging to the family of disintegrins that are derived from snake venoms, is a potent inhibitor of platelet aggregation. Echistatin is a potent inhibitor of bone resorption in culture. Echistatin is a potent antagonist of αIIbβ3, αvβ3 and α5β1[1][2][3][4]. [1]. J Musial, et al. Inhibition of platelet adhesion to surfaces of extracorporeal circuits by disintegrins. RGD-containing peptides from viper venoms. Circulation. 1990 Jul;82(1):261-73.[2]. M Sato, et al. Echistatin is a potent inhibitor of bone resorption in culture. J Cell Biol. 1990 Oct;111(4):1713-23.[3]. C C Kumar, et al. Biochemical characterization of the binding of echistatin to integrin alphavbeta3 receptor. J Pharmacol Exp Ther. 1997 Nov;283(2):843-53.[4]. I Wierzbicka-Patynowski, et al. Structural requirements of echistatin for the recognition of alpha(v)beta(3) and alpha(5)beta(1) integrins. J Biol Chem. 1999 Dec 31;274(53):37809-14.