Epithelial Cellular Adhesion Molecule (EpCAM), also known as KS1/4, gp40, GA733-2, 17-1A, and TROP?1, is a 40 kDa transmembrane glycoprotein that consists of a 242 amino acid (aa) extracellular domain with two EGF?like repeats, a 23 aa transmembrane segment, and a 26 aa cytoplasmic domain.