Interleukin-6 (IL6) is a multi-functional cytokine, produced by variety of cells including T-cells, B-cells, monocytes, fibroblasts, keratinocytes, endothelial cells, mesangial cells, astrocytes and bone marrow stroma cells. It is involved in the induction of B-cell differentiation, growth promotion of myeloma cells and proliferation and differentiation of T cells. IL6 can regulate immune responses, acute phase reactions and hematopoiesis.