IL6 and central nervous system cancer: On the contrary, the MeHg exposure with the highest concentration (5 μM-MeHg) used in this study induced a low IL-6 production level measured in C6 glioma cells, while an intermediate concentration (2.5 μM) MeHg provoked an increase in IL-6 levels, on treated cells for 8 h and 16 h (Chang, 2007).