Expanded autologous “MIL” (marrow infiltrating lymphocytes) from multiple myeloma patients using anti-CD3/CD28 stimulation and IL-2 revealed that the bone marrow contained a high number of myeloma reactive T cells (relative to blood derived T cells from the same patients) capable of targeting both mature and precursor myeloma cells in vitro (97). Here, CD28 is linked to plasma cell myeloma.