Moreover, melatonin, a hormone with known anticancer properties [50], has been shown to suppress osteosarcoma stem cells by downregulating Sox9-mediated signaling pathways, inhibiting the migration and invasion of osteosarcoma cells, inhibits the sarcosphere formation of osteosarcoma stem cells, and regulates EMT markers in osteosarcoma cells. Here, SOX9 is linked to osteosarcoma.