Another study using GBM cell lines U87 and A172 in vitro and in vivo shows that EGFR cooperates with EGFRvIII to induce macrophage infiltration by upregulation of chemokine C-C motif ligand 2 (CCL2) through the KRAS pathway, one of the major downstream pathways of the EGFR (33). This evidence concerns the gene CCL2 and glioblastoma.