An intrinsic tumour eviction mechanism in Drosophila mediated by steroid hormone signalling.

Polycomb group proteins are epigenetic regulators maintaining transcriptional memory during cellular proliferation. In Drosophila larvae, malfunction of Polyhomeotic (Ph), a member of the PRC1 silencing complex, results in neoplastic growth. Here, we report an intrinsic tumour suppression mechanism mediated by the steroid hormone ecdysone during metamorphosis.