N Logistic regression. Also this approach allows assessing the contribution of each variable to classification: in fact, the Columns 2-6 report five of the most promising amino acid properties for predicting the peptide reactivity: antigenicity [9] , accessibility [10] , hydrophilicity [11] , flexibility [12] and predicted beta-turn propensity [13] . doi:10.1371/journal.pone.0023616.t001 estimated regression coefficients provide an easy way to evaluate the reliability of the model. Moreover there are no assumptions about the probability distribution of the attributes. However, in the model that we have exploited we supposed that they were not strongly correlated.