ACLY and osteosarcoma: Therefore, this study confirmed that BMSCs derived exosomes can transfer XIST into osteosarcoma cells, promote the growth and metastasis of osteosarcoma, combine with miR-655 and down-regulate its level to promote ACLY expression, resulting in increased lipid synthesis and the increase of signal activity of β-catenin, which is the mechanism of the action of XIST.Although the collection of large clinical samples is a time-consuming and demanding work, the preclinical research results gave us confidence.