TSSC3 is reduced in human osteosarcoma cell lines.14, 15, 16, 17 We observed that both RanBP9 and TSSC3 mRNA and protein expressions were significantly decreased not only in the malignant transformed hFOB1.19 (MTF) osteoblasts as compared with hFOB1.19 osteoblasts, but also in the highly metastatic MTF cell lines (cell lines derived from high-grade osteosarcoma) as compared with the less-metastatic SaOS2, U2OS or MG63 cell line (a cell line derived from low-grade osteosarcoma) (Supplementary Figures S2a and b). Here, RANBP9 is linked to osteosarcoma.