Synonyms: Interleukin 6 (interferon, beta 2) Recombinant human IL-6 is an important pro-inflammatory and anti-inflammatory cytokine expressed by many types cell including: T and B cells, macrophages, endothelial cells, fibroblasts, monocytes , keratinocy and certain tumor cells. It Is a multifunctional cytokine that modulate several physiologic processes such as hematopoiesis, stimulation of immunoglobulin synthesis, maturation and activated B cells, differentiation of T lymphocytes and regulation of the hepatic acute-phase response. IL-6 is also produced by muscle, is discharged into the bloodstream after muscle contraction and acts to increase the breakdown of fats and to improve insulin resistance. The binding of il-6 to its receptor triggers the association of a hetheromeric IL-6R/gp130 complex, which activates JAK/ STAT1 cascade. In a mechanism known as trans- signaling, complex of soluble IL-6/IL-6R elicit responses from gp130-expressing cells that lack cell surface IL-6R, this enable a wider range of cell types to respond to IL-6.