IL6 and immune system disorder: Sepsis involves complex network effects of multiple systems, including inflammation, immune dysfunction, coagulation dysfunction, endothelial injury, multiple organ injury, and shock, etc. We have shown that CAT-PEG can effectively downregulate the production of TNF-α and IL-6 by activated leukocytes, suppress the level of AST, ALT, TNF-α, and IL-6 in the mice with induced sepsis, leading to significantly reduced mortality rate.