Secondly, regarding the invasion and metastasis of osteosarcoma, studies have shown that overexpression of chromobox protein homolog 4 (CBX4) in osteosarcoma cell lines and tissues leads to the recruitment of GCN5 to the Runx2 promoter, upregulating Runx2 at the transcriptional level and thus promoting tumor metastasis. Here, RUNX2 is linked to osteosarcoma.