We first examined H3K27me3 expression in LNCaP-EnzR cells and other prostate cancer cell lines and found that H3K27me3 was much lower in LNCaP-EnzR cells than in other late-stage prostate cancer cells (Fig. 4n; Supplementary Fig. S22a, b), suggesting that the decrease in H3K27me3 might be connected to the increased expression of TDO2 at the CRPC stage. Here, TDO2 is linked to prostate carcinoma.