Meta- or pooled analyses of GST genetic polymorphism and BC risk, indicated that GSTM1 null genotype may be the moderate risk factor (Jiang et al. 2011; Zhang et al. 2011a, b), followed by GSTP1 105Val allele (Kellen et al. 2007; Wu et al. 2012). The gene discussed is GSTM1; the disease is breast cancer.