For GSE40525 data set, triples of miRNAs have the best discriminant capacity, and the top 5 significant pathways for the best triple are: Fatty acid biosynthesis, PI3K-Akt signaling pathway, Prostate cancer, TGF-beta signaling pathway and p53 signaling pathway, all of which have pvalues below 5×10−7. This evidence concerns the gene TP53 and prostate cancer.