Interleukin-6 (IL-6) is a protein that in humans is encoded by the IL6 gene. IL-6 is an interleukin that acts as both a pro-inflammatory and anti-inflammatory cytokine. It is secreted by T cells and macrophages to stimulate immune response to trauma, especially burns or other tissue damage leading to inflammation. IL-6 is one of the most important mediators of fever and of the acute phase response. IL-6 is also essential for hybridoma growth and is found in many supplemental cloning media such as briclone. Bowcock et al. (1988) assigned the IL6 gene to chromosome 7p21. By in situ hybridization and Southern blot analysis of mouse-human hybrid cell lines, Sutherland et al. (1988) mapped the IL-6 gene to chromosome 7p15.