Composition of the Johnson data.

<p>The pie charts depict the fractions of eluted peptides that were predicted to bind to HLA-A*02:01, B*15:01, both, or neither of the two alleles. Predictions were only performed for peptides of 8–13 amino acids in length (<i>n</i> = 4113 for human-derived peptides, <i>n</i> = 103 for vaccinia). The Venn diagrams indicate the number of source proteins these peptides originated from.