The retinoic acid like {HEAD ~ activity} of {TAIL ~ these compounds} is confirmed through the classic measure of retinoic acid activity involving the effects of retinoic acid on ornithine decarboxylase 
of
The retinoic acid like { HEAD ~ activity } of { TAIL ~ these compounds } is confirmed through the classic measure of retinoic acid activity involving the effects of retinoic acid on ornithine decarboxylase
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH