TIMP1 and osteosarcoma: Different cellular signaling pathways regarding other between two mitochondria-related signature score groups of osteosarcoma cells and microenvironment cells are shown in Figures 6G, H, in which CD63, COL1A1, COL1A2, and TIMP1 were the most active signaling pathways in osteosarcoma cells with the high mitochondria-related signature score.