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