B-cell depletion has ambivalent effects on the course of immune diseases. The figure is a schematic representation of the findings of Matsushita et al.75 During the course of EAE, B cells play opposite overlapping roles. Depending on the timing of anti-CD20 antibody administration, the net clinical effect can be deleterious, neutral, or beneficial. Dashed lines indicate the severity of EAE in untreated control animals.