CDKN2C (cyclin-dependent kinase inhibitor 2C (p18, inhibits CDK4). When we compute the correlations of the probes expressions with the Normalized Shannon Entropy values of the samples, the gene that has the most negative correlations is CDKN2C (cyclin-dependent kinase inhibitor 2C -p18, inhibits CDK4 -NM_078626), which has been previously associated with the transition from prostatic intraepithelial neoplasia (PIN) to prostate cancer [68] Figure 12 . We plot the values of two modified statistical complexities, which we will call M-Gleason 3 and M- Gleason 5. Instead of using the equiprobable distribution as our probability distribution of reference (for the computation of the Jensen-Shannon Divergence of the gene expression profile to this distribution), as required for the MPR-Statistical Complexity calculation, we used a different one. For the M-Gleason 3, the probability distribution of the reference is obtained averaging all the probability distributions of the samples that have been labelled as Gleason 3 (analogously, we calculated M- Gleason 5) . This is analogous to our approach in melanoma ( Figure 5 ) in which we used normal and metastatic samples as reference sets for a modified statistical complexity. We observe that, even in this case, 02_003E and 03_063 continue to appear as outliers. In addition to the evidence, we have observed that the deletion of these two samples did not significantly alter the identification of biomarkers. doi:10.1371/journal.pone.0012262.g013 Samples 02_003E and 03_063 seem to be outliers to this trend, and in the case of 03_063 the sample is not even close to a hypothetical linear fit which seems to be the norm for all the samples. Figure 13 will provide further evidence that may indicate that these two samples are outliers or not to the overall trend. doi:10.1371/journal.pone.0012262.g012 with the dedifferentiation process, with preoperative PSA levels and the percent of Gleason 4 and 5 cancers [338] .