UCP3 and neoplasm: In response to topical application of the tumour promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) (treatment timeline Fig. 1a), Tg.AC mice rapidly formed tumours; however, bi-transgenic K5-UCP3/Tg.AC mice phenocopied the potent resistance to tumour formation observed in the K5-UCP3 background (Fig. 1b–e), indicating that UCP3 overexpression likely interferes with tumour promotion.