CD19 and myasthenia gravis: In support of this, Rituximab, which targets B cells and short-lived plasma cell precursors, but not long-lived plasma cells (typically CD19+, CD20−), demonstrates a strong efficacy in MuSK-MG [118,119] but controversial efficacy in treating AChR-MG, in which removal of the thymus, where long-lived plasma cells reside, has been demonstrated to be clinically beneficial [16].