{HEAD ~ These proteins} are distinct from {TAIL ~ the drosophila hedgehog protein} which, for clarity, will be referred to hereinafter as “Dros HH” 
are distinct from
{ HEAD ~ These proteins } are distinct from { TAIL ~ the drosophila hedgehog protein } which , for clarity , will be referred to hereinafter as “ Dros HH ”
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH