ml138ML138 (CID 44601470) is a hhly selective agonist at kappa opioid receptors (KOR) that potently activate G protein coupling but weakly interact with β arrestin2.100 Patents (Medical) associated with ML138. Login to view more data. 100 Deals associated with ML138. Login to view more data. R&D Status. 10 top R&D records. Login. to view more data.