1. Molecular Oncology Group; Cancer Research UK Manchester Institute; Wilmslow Road Manchester M20 4BX UK
2. Signal Transduction Team, Division of Cancer Biology; Institute of Cancer Research; London SW3 6JB UK
3. Experimental Pathology Laboratory; Cancer Research UK London Research Institute; London WC2A 3LY UK
4. Melanoma Unit; Royal Marsden Hospital; London SW3 6JJ UK
5. Department of Surgery; Royal Marsden Hospital; London SW3 6JJ UK
6. Laboratory for Translational Cell and Tissue Research; University Hospitals Leuven, Katholieke Universiteit Leuven; Herestraat 49 3000 Leuven Belgium