A three-amino-acid sequence (Arg-Gly-Asp) that acts as a universal ‘docking code’ recognized by integrins on cell surfaces.The RGD (arginine-glycine-aspartate) tripeptide sequence is the minimal recognition motif for several integrin receptors, including αvβ3, αvβ5, and αIIbβ3. Found in extracellular matrix proteins (fibronectin, vitronectin, fibrinogen), RGD mediates cell adhesion, migration, and survival signaling. Cilengitide is a cyclic RGD pentapeptide designed to competitively inhibit αvβ3/αvβ5 integrin binding. Eptifibatide contains a KGD (lysine-glycine-aspartate) motif that selectively blocks αIIbβ3 on platelets. RGD-based targeting is also used in radiolabeled peptide imaging.S↑ Top