MM cells are generally considered to be weak APCs and express activating co-stimulatory signals on their surface, such as CD40,CD80/86,4-1BBL,OX40L,CD70,B7 relative protein1(B7RP1) molecules that binding to CD40L,CD28,4-1BB,OX40,CD27, inducible co-stimulator(ICOS) receptors on T cells, respectively (9). Here, CD80 is linked to Miyoshi myopathy.