Interleukin-6 Receptor (IL-6R) is a single trans-membrane protein that is the receptor for Interleukin-6 (IL-6). IL-6R forms a hexameric complex upon binding 2 molecules of IL-6 and two molecules of glycoprotein 130 (gp130) which activates intracellular JAK/STAT pathways. Although the normal form of IL-6R is the membrane-bound 80 kDa subunit, a soluble form of IL-6R (sIL-6R) can be generated physiologically by limited proteolysis or alternative splicing. sIL-6R binds to both IL-6 and gp130 generating intracellular signaling. In the immune system, sIL-6R is produced by both naïve and memory CD4 T-cells and strongly augments IL-6 ligand’s induction of Th-17 cells.Recombinant human Soluble IL-6 Receptor Alpha (rhsIL-6R alpha) with an N-terminal His tag produced in Sf9 insect cells is a single glycosylated polypeptide chain containing 350 amino acids. A fully biologically active molecule, rhsIL-6R alpha has a molecular mass of 50kDa analyzed by reducing SDS-PAGE and is obtained by proprietary chromatographic techniques at GenScript.