Further analysis on the differences between metastatic and non-metastatic samples revealed six intersection genes—AIM2, RPL22L1, PDPN, PKIB, GZMA, and MDM2—that related to metastasis potential of osteosarcoma and the observed gene expression differences resulted from the changes in methylation (Figure 2A). This evidence concerns the gene RPL22L1 and osteosarcoma.