ERG and prostate cancer: For this study, we had selected androgen receptor protein expression because of its pivotal role in prostate cancer, TMPRSS2:ERG fusion because this is the most common molecular alteration in prostate cancer, 11 different chromosomal deletions because these represent the most common recurrent genomic alterations in prostate cancer after TMPRSS2:ERG fusions, and tumor cell proliferation (Ki-67 labeling index).