Multiple myeloma is a tumor of elderly with longtime antigen exposure, and subsequent over-expression of PD 1 to indicate myeloma antigen–exposed T cells, viral antigen–specific memory T cells, or immune senescent cells10, up-regulation of PD1 on CD8+, CD4+T cells, and NK cells is observed in MM11, blocking of PD1 will restore T and NK cell functions. Here, CD4 is linked to plasma cell myeloma.