VEGFA and osteosarcoma: Vascular endothelial growth factor (VEGF) is highly expressed in osteosarcoma and can act as a paracrine molecule in the tumor microenvironment to promote tumor angiogenesis, as well as an autocrine molecule to promote tumor proliferation and metastasis, thus promoting the occurrence and development of osteosarcoma and being related to the prognosis of osteosarcoma.