. . . . . . . "[To further understand the human implications of genetic variation within the opioid system in pain and opioid-mediated placebo responses, we investigated the association between the functional single-nucleotide polymorphism (SNP) in the ?-opioid receptor gene (OPRM1), A118G, and psychophysical responses, personality traits, and neurotransmitter systems (dopamine (DA), opioid) related to pain and placebo analgesia.]. Sentence from MEDLINE/PubMed, a database of the U.S. National Library of Medicine."@en . . . . . "2017-02-19"^^ . . "Gene-disease associations inferred from text-mining the literature."@en . "DisGeNET evidence - LITERATURE"@en . "2017-10-17T13:15:08+02:00"^^ . . . . . . . . . . . "v5.0.0.0" . "v5.0.0" .