References: Andersson, J., J. Abrams, et al. Concomitant in vivo production of 19 different cytokines in human tonsils.1994. Immunology 83(1): 16-24.
Gaines Das, R. E. and S. Poole. The international standard for interleukin-6. Evaluation in an international collaborative study. 1993. J Immunol Methods 160(2): 147-53.