OPRM1 and psoriasis: Furthermore, the G allele of the rs1799971 (OPRM1) was also significantly associated with increased psoriasis risk in the additive and dominant models (ORadditive = 1.75, 95% CI 1.27–2.43, p = 0.001, ORdominant = 1.82, 95% CI 1.26–2.63, p = 0.001) (Table 3).