[Soluble IL-6 receptors].

Both subunits of IL-6 membrane--associated receptor, IL-6R and gp130 can exhibit in a soluble forms--sIL-6R and sgp130 respectively. Soluble IL-6 receptor (sIL-6R) can bind IL-6 and mediate IL-6 function through association with gp130 which is the signal transducing protein. In contrast to other receptors, sIL-6R has a potential to enhance the IL-6 biological function. sIL-6R and sgp130 were found in appreciable amounts in body fluids, although the exact cellular source and function of these proteins are not completely clear.