Comparison of PPV (cancer diagnosis) between the method without-filtering (WF, pink) with variance-filtering (VF, brown) in the UKOPS data set. The PPV values shown are those obtained from beta-values. PPV values in test sets are shown for evaluation set sizes consisting of the top 200, 500, and 1000 diagnosis-associated-CpGs in the training sets. A total of 50 training-test set partitions were used. All p-values shown are from a Wilcoxon-rank sum test.