1 Centre for Inflammatory Diseases, Department of Immunology and Inflammation, Imperial College London, London, UK; Department of Cellular Pathology, North West London Pathology, London, UK. Electronic address: c.arthurs@imperial.ac.uk.
2 Centre for Inflammatory Diseases, Department of Immunology and Inflammation, Imperial College London, London, UK; Department of Cellular Pathology, North West London Pathology, London, UK.