The composition comprises a polyvalent agent that binds to {TAIL ~ a highly expressed cell surface antigen present} on {HEAD ~ the surface} of a cell 
The composition comprises a polyvalent agent that binds to { TAIL ~ a highly expressed cell surface antigen present } on { HEAD ~ the surface } of a cell
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH