In this review in Cell Metabolism, Ludwig Oxford’s Colin Goding and Custodia García-Jimenéz (Madrid) propose that invasive behaviour in cancer is caused either by nutrient or oxygen limitation within the tumour, or by signals from immune cells or therapy that hijack the cell’s starvation response to impose a pseudo-starvation state. By explaining how many apparently unrelated triggers for invasion converge on a single cell survival strategy, similar from bacteria to man, the authors identify a therapeutic vulnerability in invasive cancer cells.