CSF2 and neoplasm: Furthermore, co-culture of HSVGM-CSF-infected tumor cells with iDCs resulted in increased secretion of GM-CSF and tumor necrosis factor alpha (TNF-α), together with decreased production of the immunosuppressive cytokine interleukin-10 (IL-10) (Figure 1E); virus-infected melanoma cells secrete GM-CSF, as expected (Figure 3); therefore, it is most likely that the GM-CSF production is derived from infected tumor cells.