However, little is known about the role of angiogenesis andproangiogenic factors, such as VEGF, in the development and biologic activityof malignant bone tumors [16] though several clinicalstudies have found that many osteosarcoma patients with pulmonary metastasis hadprimary tumors with high levels of VEGF expression [17]. The gene discussed is VEGFA; the disease is bone cancer.