Our results also demonstrate that, despite CCR2 and CXCR4 expression, which is related to leukocyte recruitment to the tumor site mediated by inflammatory chemokines [64], in the human primary NK cells we established, chemokine gene expression was low both in the GlioVis-analyzed patients with GBM and in the microarray-analyzed spheroids; furthermore, few NK cells infiltrate into the GBM [19,20]. Here, CXCR4 is linked to neoplasm.