CD40 and myeloid sarcoma: However, comparison of cell surface CD40 expression on B-lymphocytes between healthy controls and MS patients (Fig 3) showed that CD40 expression was significantly lower in MS patients compared to healthy controls in all CD19+ B-lymphocytes (Fig 3A; p <0.0001), as well as in the naïve B lymphocytes\ (Fig 3C; p <0.0001), classical memory B-lymphocyte (Fig 3D; p = 0.0001) and IgM memory B lymphocyte subsets (Fig 3E; p = 0.0004).