Interleukin-6 (IL-6) is a protein cytokine that was discovered in the 1980s. It is also known as B-cell stimulatory factor 2, hepatocytestimulating factor, hybridoma growth factor, or interferon (IFN)-β2. IL-6 participates in inflammation, immune response, and acts in the coordination of developmental, neuronal, and metabolic processes (1). IL-6 acts as a transmitter of alarm signals to the whole organism, indicating the occurrence of an emergency such as infection or tissue damage. Human IL-6 is made up of 212 amino acids, including a 28-amino-acid signal peptide, and its gene has been mapped to chromosome 7p21. Although the core protein is 20 kDa, glycosylation accounts for the size of 21–26 kDa of natural IL-6.