One is {TAIL ~ a cell delivery agent} for delivering a biologically active protein or {HEAD ~ peptide} to a cell as described above 
One is { TAIL ~ a cell delivery agent } for delivering a biologically active protein or { HEAD ~ peptide } to a cell as described above
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH