When analyzing these 20 candidates, the following gene transcripts appeared to be increased in PCa compared with the normal prostate gland: SLC12A2, DDAH1, GDF15, APOE, NDRG1, and YWHAZ. Although we did not validate the MS results on the protein level, there are previous reports that show increased protein expression of DDAH1, GDF15, APOE, NDRG1, and 14-3-3ζ/δ in PCa tissues compared with benign prostate tissues22,36–39. This evidence concerns the gene DDAH1 and posterior cortical atrophy.