For antiangiogenic drugs, our lab has repeatedly shown that simple primary tumour models tend to over-predict clinical efficacy compared to more sophisticated metastatic tumour models in which orthotopically grown primary tumours are surgically resected so that the VEGF/VEGFR2 pathway inhibitors can be administered at clinically relevant time points to either treat microscopic metastatic disease in the perioperative setting19–21 or macroscopic metastases in the advanced disease setting.22 Here are two examples. This evidence concerns the gene VEGFA and metastatic neoplasm.