1. Cancer Research UK Cambridge Institute; Li Ka Shing Centre; Cambridge CB2 0RE UK
2. Department of Chemistry; University of Cambridge; Cambridge CB2 1EW UK
3. A. I. Virtanen Institute for Molecular Sciences; University of Eastern Finland; Neulaniementie 2 70211 Kuopio Finland
4. Department of Molecular Biotechnology and Health Science; Molecular Imaging Center; Via Nizza 52 10126 Turin Italy