Biomarker comparison. Best 10 peaks (i.e. peptide signals) from the Ovarian cancer dataset selected using PPC (left) and t-statistics (right). Each small panel shows a histogram of peak heights in the training set at one m/z value for healthy patients (top) and cancer patients (bottom). Vertical line corresponds to the estimated optimal height split point (see  for details). The proportions of samples in each class having peaks higher than the split point are indicated (e.g. for top left corner panel these proportions are respectively 0.13 and 0.68). Notice that the two selected sets have only 3 peaks in common.