In this study, the human proenkephalin (hPPE) gene, which is a classical tool widely used in previous studies [11] on transgenic analgesia, was chosen as a target gene to be transfected into human bone marrow mesenchymal stem cells (hBMSCs), followed by intrathecal injection into a rat bone cancer pain (BCP) model [12]. This evidence concerns the gene PENK and bone neoplasm.