CD8A and Epstein-Barr virus infection: Whether the CD8+ T‐cell response to EBV is decreased in BD could be addressed by immunological studies of the response of peripheral blood CD8+ T cells to EBV antigens in individuals with BD and in EBV‐seropositive healthy individuals, as have been used to demonstrate defective CD8+ T‐cell control of EBV infection in MS.54