1. Centre for Neuromuscular Disease, Department of Neuromuscular Diseases UCL Institute of Neurology, and National Hospital of Neurology and Neurosurgery London UK
2. Neuroimmunology and CSF Laboratory Institute of Neurology, National Hospital for Neurology and Neurosurgery, University College London NHS Foundation Trust London UK
3. Cancer Division University College London Hospitals NHS Foundation Trust London UK
4. Division of Neuropathology National Hospital of Neurology and Neurosurgery, UCL Hospitals NHS Foundation Trust London UK
5. Department of Neuro‐Oncology National Hospital of Neurology and Neurosurgery London UK
6. Haematopathology Unit, Department of Cellular Pathology University College London Hospitals NHS Foundation Trust London UK