IL-6 was cloned as B cell stimulatory factor-2 (BSF-2) in 1986 (Hirano et al. 1986). This molecule has various biological activities; a strong stimulatory effect on growth of murine plasmacytoma and human myeloma, its functions as a hepatocyte stimulating factor, and the induction of acute phase reaction. IL-6 knockout (KO) mice revealed the inhibition of the antiviral antibody response after immunization with a vesicular stomatitis virus, compared with wild-type (WT) mice. Thus, IL-6 is a pleiotropic cytokine that is involved in the physiology of virtually every organ system.
We thank our colleagues in our laboratory for helpful discussion. This work was supported by the Program for Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation and Chugai-Roche Pharmaceutical Co. Ltd., Tokyo, Japan.