EZH2 and prostate cancer: In one of the most significant papers on prostate cancer recently, a tumor progression array was used to show that the expression of a novel protein, EZH2, correlated with aggressiveness of disease.31 (3) In prognostic (patient outcome) arrays, correlation of tissue microarray-derived data with clinical follow-up, to assess prognosis or patient outcome, is of significant interest to clinicians and their patients.4 An example is the study of the expression of the EZH2 protein in prostatic cancer.