IL17A and autoimmune disease: Finally, we used FCM to examine the effects of PEG-HCCs on the production of proinflammatory cytokines involved in autoimmune diseases, such as MS, by antigen- or mitogen- stimulated T cells and found a ~30% reduction in the intracellular levels of the TH1 cytokines interleukin (IL)-2 and interferon (IFN)-γ, but no effect on expression levels of the TH17 cytokine IL-17A (Fig. 4e and Supplementary Fig. S14), suggesting distinct cell signaling pathways are altered by PEG-HCCs.