While the m/z values of the peptide fragments can easily be calculated from the corresponding amino acid sequence, the exact intensities of those fragments depend on the unique chemistry of each peptide sequence . By predicting the fragment ion intensities we can thus generate an MS/MS spectrum. Accurate prediction of these fragment ion intensities has been an active area of research for a number of years . It is important to note that because of the distinct spectral characteristics of immunopeptides, fragment ion intensity prediction tools should be retrained using immunopeptidomics data to drastically improve prediction accuracy .