OPCML and opioid use disorder: In addition, there was downregulation of several opioid-related transcripts, including of postsynaptic opioid-binding cell adhesion molecule (OBCAM) OPCML, which is downregulated during chronic opioid agonist exposure47–49; the closely related neurotrimin (NTM); ephrin-B1 receptor (EPHB1), which colocalizes and interacts closely with ephrin-B2 receptor50,51 as a mediator of OPCML signaling49; and non-coding RNA AC073225.1, previously reported to show decreased expression in opioid use disorder (OUD)52.