CES1 and neoplasm: Immunohistochemical (IHC) staining was carried out to determine the CES1 protein expression in the PCa specimens, and we found that the protein expression of CES1 was significantly lower in the PCa tissues compared with that in the normal prostate tissues, and high expression was negatively related to Gleason score and tumor stage (Figure 3B), indicating that CES1 is a key gene in PCa.