Drugs that upregulate the concentration of {HEAD ~ cAMP} in {TAIL ~ cells} are well known 
in
Drugs that upregulate the concentration of { HEAD ~ cAMP } in { TAIL ~ cells } are well known
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH