Alternatively, other targeting devices may be used such as attachment of the amplifier to {TAIL ~ a porphyrin} or other tumor seeking {HEAD ~ moiety} 
Alternatively , other targeting devices may be used such as attachment of the amplifier to { TAIL ~ a porphyrin } or other tumor seeking { HEAD ~ moiety }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD