Receiver operating characteristic curves. ROC curves compare true-positive rates with false-positive rates of different PF cutoffs for prediction of the presence or absence of individual gene variants and homologous groups. Error rates are shown for genes (dotted lines) and homologous groups (solid lines), computed from EGD-e (red) and J2-071 (black) control hybridizations. Circles indicate the chosen PF cutoff of 0.6 for classifying gene variants. Triangles indicate the chosen PF cutoff of 0.6 for classifying homologous groups.