Next, we tested whether melanoma cells may alter production of common cytokines, chemokines and growth factors by DRG neurons using the Proteome Profiler Mouse Array kit and revealed a significant up-regulation of expression of chemokines that attract myeloid-derived suppressor cells, including CCL2, CCL3, CCL5, CXCL1, CXCL2 and CXCL12 (Fig 5). Here, CCL2 is linked to melanoma.