GSTM1 and cancer: The analysis, based on the BIC index, favored the model without interaction terms (M2), ruling against the hypothesis that the cancer risk predictivity of CA frequency could be modified by these polymorphisms, i.e., BIC(M3) = 481.9 > BIC(M2) = 473.1 for GSTM1 and BIC(M3) = 365.5 > BIC(M2) = 357.7 for GSTT1.