{{Genotype
|allele1=G
|allele2=G
|rsid=1799971
|magnitude=2.6
|repute=Bad
|summary=more pain
}}
[http://blog.23andme.com/2009/08/13/snpwatch-genetic-variation-in-morphine-receptor-may-play-a-part-in-coping-with-social-rejection/] associated with needing more morphine for pain relief after surgery and heightened responses to social rejection.  

stronger cravings for alcohol; if alcoholic, naltrexone treatment 2x more successful