It is noteworthy that several transcripts (e.g., Ki67) (Supplemental Fig. S2A) display stronger differential expression between primary and metastatic cancer than EZH2. This further suggests that association of high EZH2 with cancer aggressiveness might reflect the increased cell proliferation occurring in advanced stages of prostate cancer (e.g., see Tomlins et al. 2007). This evidence concerns the gene EZH2 and prostate cancer.