James W. Ajioka (corresponding author)
University Lecturer, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK. Tel: +44 (0)1223 333 923/329; Fax: +44 (0)1223 333 346; E-mail: jwa@mole.bio.cam.ac.uk

Jennifer M. Fitzpatrick
PhD Student, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK. E-mail: jmf40@mole.bio.cam.ac.uk

Christopher P. Reitter
Research Assistant, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK. E-mail: cpr@mole.bio.cam.ac.uk