CCL2 and malignant peripheral nerve sheath tumor: Importantly, the increased Ccl2 mRNA expression induced by CM from both mouse PNF and MPNST precursor cells was effectively inhibited by 200 nM MSU-42011 (PNF, p = 0.0007; MPNST precursor, p < 0.0001) and 50 nM selumetinib (PNF, p = 0.0012; MPNST precursor, p < 0.0001) and further reduced by their combination (PNF and MPNST precursor, p < 0.0001) compared to the vehicle treatment.