Systems that biologists discover are often named after the first ligand to be used on them: cannabinoid, nicotine, opioid, to bend a few. There is no aspirin s

Systems that biologists discover are often named after the first ligand to be used on them: cannabinoid, nicotine, opioid, to bend a few. There is no aspirin system but salicylates bind to COX, so we may well have had a salicylate receptor if things went slightly differently.