Trogocytosis challenges the cellular specificity of lineage markers and monoclonal antibodies

The transfer of surface molecules between cells by trogocytosis challenges the concept of cell type-unique surface markers and indicates that monoclonal antibodies used for therapeutic purposes may be less specific than previously thought. Furthermore, trogocytosis may transfer functional properties to new cell types. This process could be used experimentally to trace disease-relevant cell–cell interactions. This Comment article proposes that the transfer of surface molecules between interacting cells by trogocytosis might affect the cellular specificity of monoclonal antibodies, as well as the functionality of receiving cells.