PCAT7 and bone metastasis: PCAT7 expression was further validated in our sample of 20 paired fresh tissues of PCa, as well as in the 31 PCa tissues without bone metastasis (PCa/nBM), 26 PCa tissues with bone metastasis (PCa/BM), and 11 metastatic bone tumor tissues (bone tumors formed by the metastatic prostate cancer cells in bone, Bone).