CCL2 and meningioma: Additionally, we investigated the presence of miR-21 and the different cytokines: Interleukin-6 and Interleukin-10 (IL-6 and IL-10), Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) and Chemokine (C-C motif) Ligand 2 (CCL2) in the plasma of 28 patients diagnosed with meningioma.