FGF23 and osteosarcoma: The lentiviral shRNA-mediated “knockdown” of FAM20C in mouse preosteoblasts MC3T3-E1 cells, human Saos-2 cells (osteoblasts isolated from human osteosarcoma) and human mesenchymal stem cells (hMSC) revealed a remarkable downregulation of DMP1 (Figure 9A–9C), along with a significant upregulation of FGF23 in both the human and mouse cell lines (Figure 9D–9F), indicating that FAM20C may function similarly in humans and mice.