Receiver operating characteristic (ROC) analysis. Receiver Operating Characteristic (ROC) curves were determined using a plant-specific test set of 80 positive and 185 negative sequences. Prediction models tested are distinguished by line type: HMM80, solid black; NMT, solid grey; BGM, dotted black, Expasy open circles. Areas under the curves, an indication of model performance, were: HMM80, 0.969; NMT, 0.892; BGM, 0.874, Expasy 0.811. Higher numbers indicate better performance.