Association of the SOD2 (rs2758339 and rs5746136) polymorphisms with the risk of heroin dependency and the SOD2 expression levels.

Background: Superoxide dismutase-2 (SOD2, OMIM: 147460) is involved in the detoxification of superoxide anions. The SOD2 mRNA level is down-regulated in cells exposed to morphine. Oxidative stress plays an important role in drug dependency.