EPCAM and neoplasm: Taking as an example, catumaxomab is an intact trifunctional BsAb with one arm targeting human epithelial cell adhesion molecule (EpCAM) on tumor cells, one arm targeting CD3 on T cells and the Fc region binding to Fcγ receptor type I, IIa and III on effector cells such as macrophages, nature killer cells and dendritic cells [32].