In the in vivo model, animals bearing xenografts of both neuroblastoma cell lines were treated with low doses of vinblastine; or a monoclonal neutralizing antibody (DC101) that blocks the function of vascular endothelial growth factor receptor 2 (vegfr2) and, hence, vascular endothelial growth factor (vegf) itself; or both agents together. The gene discussed is KDR; the disease is neuroblastoma.