Of these, further study of the role of CCL2 in GBM invasion may be particularly warranted, as expression levels were not only significantly increased in GBM-MG co-culture (vs. GBM-single or MG-single cultures) but also compared to the Mix control, consistent with synergistic activation of CCL2 secretion due to GBM-MG crosstalk. This evidence concerns the gene CCL2 and glioblastoma.