The activation of macrophage phagocytosis of tumor cells and co-presentation of their antigens may synergize with the chemoattractant activity of CXCL12 towards monocytes and macrophages, with CXCR4-TCR co-signaling in the immune synapse and with BCR co-signaling in mature B cells. This evidence concerns the gene CXCL12 and neoplasm.