It is contemplated that {HEAD ~ growth factor protein product} may be expressed using nucleotide sequences which differ in {TAIL ~ codon usage} due to the degeneracies of the genetic code or allelic variations 
It is contemplated that { HEAD ~ growth factor protein product } may be expressed using nucleotide sequences which differ in { TAIL ~ codon usage } due to the degeneracies of the genetic code or allelic variations
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH