(A) ROC curve illustrating the capacity of the CCV criterion to classify 4150 pairs of peptides overlapping in 11/15 positions as a model of cross-reactive peptide pairs compared to a set of 10,000 pairs of dissimilar peptides (sharing a longest common subsequence of fewer than 3/15). The analysis is done on the basis of the dataset from [1]. The logarithms of the values of CCV are used. (B) Distributions of the log CCV values for dissimilar sequences (black) vs. cross-reactive sequences (red). The optimal tradeoff between sensitivity and specificity was found for CCV = 2 (specificity = 0.926, sensitivity = 0.69, AUC = 0.904)