This had the effect of stimulating secretion of SDF-1, a powerful mediator of chemotaxis for CXCR-4 expressing killer cells, improving the homing efficiency of chimeric PBLs to bone marrow and enabling artificially induced bone metastases from prostate cancer to be treated successfully after intravenous administration of T-bodies. The gene discussed is CXCL12; the disease is prostate carcinoma.