Furthermore, to confirm the effects of cytokine neutralization or MEK inhibitor selumetinib on MEK activity, i.e., phosphorylation of ERK protein, we treated cancer spheroids cultured in RGF Matrigel with CM from stromal cells treated with vehicle (CM-V) or chemotherapy (CM-DTX) and added neutralizing antibodies against IL-6 and/or G-CSF or treated with selumetinib. Here, IL6 is linked to cancer.