MHC distance trees were derived from correlations between predicted binding affinities. For each allelic MHC-I molecule, the binding affinity was predicted for a set of 200,000 random natural peptides using the NetMHCpan method. Next, the distance between any two alleles was defined, as D = 1− PCC, where PCC is the Pearson correlation between the subset of peptides within the superset of top 10% best binding peptides for each allele. In this measure, two molecules that share a similar binding specificity will have a distance close to 0 whereas two molecules with non-overlapping binding specificities would have a distance close to 2. Using bootstrap, 100 such distance trees were generated, and branch bootstrap values and the consensus tree were calculated.