The gene for IL-6 is located at chromosome 7 whose unit transcription consists of 5 exons and 4 introns. The promoter region contains several transcription start sites with response elements for nuclear factor (NF)-κB, enhancer-binding protein beta (C/EPBβ; formerly NF-IL6), activator protein (AP)-1 (Burger 2013) and CREB transcription factor (Dendorfer et al. 1994). The protein form of human IL-6 is a glycoprotein composed of 184 amino acids with a molecular weight of 21-28 kDa, depending on its degree of glycosylation. It has a 4-helix bundle structure made up of 4 long α-helices arranged in an up-up-down-down topology (Burger 2013).