CD8A and multiple sclerosis: Recent work (56) suggests that defective CD8 T cell control of EBV reactivation in multiple sclerosis (MS) patients leads to an expanded population of EBV-infected, autoreactive B cells; this is supported by preliminary results of a Phase I clinical trial that demonstrated improvement of MS symptoms following infusion of autologous EBV-specific CD8 T cells, which are thought to bring the virus under control (57).