CCL2, a CC chemokine that stimulates CCR2, its corresponding receptor expressed on T cells [29], NK cells [30] and γδ T cells [31], is reported to be expressed by various types of cancer cells including those of glioma [17], melanoma [28], and cancers of the breast [32], prostate [33], colon [34] and lung [35]. This evidence concerns the gene CCL2 and central nervous system cancer.