A representative MS/MS spectrum of PSA. The relative ratios of PSA between 116(PCa) and 114(BPH) was 1.31. PSA was identified with 11 peptides abo-ve the 95% confidence. This Figure displays the MS/MS spectrum of one peptide from PSA. The peptide sequence: FLRPGDDSSHDLNLLR is shown(The peptides above the 95% confidence are colored green and the peptides in the other colors have lower confidence). BPH samples were labeled with 114 tags, PCa samples were labeled with the 116 tags, and BPH with local PIN samples were labeled with 117 tags. The peptide fragments including b-ion and y-ion series are shown in A and B. The quantitation information of the peptide is shown in C.