Fig. 2

Receiver operating characteristic (ROC) curve. a ROC curve based on GSTM3 mRNA expression levels. The optimal cut-off value was 0.662 with a sensitivity of 56.0 % and a specificity of 58.7 %. The area under the ROC curve was 0.564, and the p-value was 0.135. b ROC curve based on GSTM3 protein expression. The optimal cut-off value was 4, with a sensitivity of 66.5 % and a specificity of 45.0 %. The area under the ROC curve was 0.539, and the p-value was 0.311