The fully human CXCR4 mAb, MDX-1338, was recently shown to effectively block calcium flux and migration of cancer cells, induce apoptosis in various tumor cell lines in vitro and reduce tumor growth in xenograft models of acute myeloid leukemia, non-Hodgkin lymphoma and multiple myeloma [29]. Here, CXCR4 is linked to plasma cell myeloma.