HEPACAM and myeloid sarcoma: Specifically, a monoclonal antibody in the CSF of an MS patient was found to bind the EBNA1 epitope of Epstein Barr virus (EBV) and cross‐react with GlialCAM (protein glial cell adhesion molecule), confirming that 20–25% of MS patients possess cross‐reactive antibodies against EBV and GlialCAM [88].