A wake-up call for hibernating tumour cells

Disseminated tumour cells (DTCs) can adopt a state of long-term dormancy. However, when and why they emerge from quiescence has remained unclear. Distinct microvascular niches are now shown to regulate this process. Mature blood vessels produce signals that sustain tumour cell quiescence, whereas sprouting microvasculature provides stimuli that reactivate DTCs, leading to metastatic relapse.