IL-6 production with increasing doses of endotoxin. IL-6 production with increasing doses of endotoxin. Mice were injected with the indicated doses of endotoxin, and plasma was harvested 2 h later. Increasing doses of endotoxin resulted in increasing plasma IL-6 levels. Note that both the IL-6 concentration (Conc.) and endotoxin dose are plotted on a log scale. The line indicates the regression through the data. Shannon Copeland et al. Clin. Diagn. Lab. Immunol. 2005; doi:10.1128/CDLI.12.1.60-67.2005