EPCAM (epithelial cell adhesion molecule) is a type I transmembrane glycoprotein, which is also known as CO171A, EGP, EGP40, GA7332, KSA, M4S, MIC18, MK1, TROP1, hEGP2. EPCAM is highly expressed in a variety of epithelial tumor tissues and promotes tumor proliferation. EPCAM contributes to various biological processes including cell adhesion, signaling, migration and proliferation. Intact EPCAM and its proteolytic fragments interact with claudins, CD44, E-cadherin, epidermal growth factor receptor (EGFR), and intracellular signaling components of the WNT and Ras/Raf pathways, respectively. EPCAM is a prognostic marker and target for primary and systemic tumor cells. Oportuzumab Monatox, an ADC targeting epithelial cell adhesion molecule (EPCAM) developed by Sesen Bio, has completed phase III clinical trials.