CYP2D6 and systemic lupus erythematosus: For example, some studies have reported that the CYP2D6*4 (odds ratio [OR]=2.0, 95% confidence interval [CI]=[1.17-3.44]; p=0.01) and poor metabolizer phenotype (OR=1.78, 95% CI=[1.25-2.53], p=0.001) are associated with SLE development.5 Other studies, on the other hand, suggested no correlation between CYP2D6*4 gene mutations and SLE.6-8 We believe that these differences are contingent on ethnic differences.