In addition, Ang-2 might be involved in a delayed resolution of cancer cell-blood clotting, as described for venous thrombosis.51 Furthermore, our findings support previous preclinical studies, which demonstrated that both Ang-2 and VEGF are crucially involved in BM formation.5,13 An important clinical question the present work does not address, is the role of radiotherapy in the context of cancer cell extravasation and in the context of the proposed mechanism. This evidence concerns the gene VEGFA and cancer.