Nature 481, 190–194 (2012); published online December 14 2011
For a cancer to metastasise, it must overcome the physiological mechanisms that normally protect against the dissemination of cells and their lodgement and growth at remote sites. The mechanisms by which invading cancer cells modify and engage with the new environment at a secondary site are poorly understood but provide potential novel avenues for therapeutic intervention. A recent report in Nature (Png et al, 2012) identifies a microRNA, miR-126, whose loss in tumour cells promotes the initiation of metastases in various secondary organs. The key targets of miR-126 in this process are found to be novel regulators of endothelial cell recruitment and angiogenesis.