VEGFA and breast carcinoma: In these in vivo mouse models, increased Ang-2 expression in brain capillary endothelial cells was directly associated with BBB disruption, further facilitating extravasation and colonization of circulating breast cancer cells in the pre-metastatic niche.5 Moreover, as expected, we observed a substantial upregulation of VEGF in cancer cells in vitro in response to hypoxia.