R S van Onkelen1,2, M P Gosselink3, J D Laman4,5, W R Schouten6. 1. Department of Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands. r.vanonkelen@gmail.nl. 2. Department of Immunology, Erasmus MC, University Medical Center and MS Center ErasMS, Rotterdam, The Netherlands. r.vanonkelen@gmail.nl. 3. Department of Surgery, Maasstad Hospital, Rotterdam, The Netherlands. 4. Department of Immunology, Erasmus MC, University Medical Center and MS Center ErasMS, Rotterdam, The Netherlands. 5. Department of Neuroscience and Medical Physiology, University of Groningen, University Medical Center, Groningen, The Netherlands. 6. Department of Surgery, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.