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