We further investigated the expression features of the remaining 9 genes (CDK1, CHEK1, CCNA2, CDC6, AURKB, EXO1, RAD51, CDC45 and BUB1B) in TCGA–PRAD, and found that upregulation of all the 9 genes were significantly associated with higher ISUP level (Gleason score, Fig. 3A1–A10), more lymph node metastasis (N, Fig. 3B1–B10) and heavier tumor load (T, Fig. 3C1–C10). This evidence concerns the gene EXO1 and neoplasm.