In addition to the discovery that ERG was the strongest predictor for BCR, we detected seven additional genes, GGT1, HDAC1, KLK2, MYO6, PLA2G7, BICD1, and CACNAID, which were differentially expressed between non-BCR and BCR prostate cancers and could independently predict BCR in patients without early clinical or pathological signs of progression at surgery. Here, KLK2 is linked to prostate cancer.