Together with standard performance measures, such as accuracy, sensitivity and specificity, we also computed the Fmeasure of the predictive model. The F-measure is the harmonic mean of precision (positive predictive value) and recall/sensitivity. As a matter of fact, in order to develop a model that is useful to generate new reactive peptides, it is important to maximize both precision and sensitivity: it means to have a high probability that the peptide predicted to be positive is really reactive and that the reactive peptides are correctly classified.