The first reported prostate tissue-specific and prostate cancer-associated, long non-coding (lnc) RNAs were differential display 3 (DD3)/(PCA3) and a prostate cancer gene expression marker 1 (PCGEM1) [58]; however, PCA3 was found to be over-expressed in virtually all prostate cancers [59,60,61]. This evidence concerns the gene PCGEM1 and prostate cancer.