Interleukin 6 (IL-6) is a cytokine with both pro-inflammatory and anti-inflammatory properties. In humans, it is encoded by the IL-6 gene. IL-6 is secreted by T cells and macrophages to promote immune response during infection and after trauma, especially inflammation resulting from burns or other tissue damage. Studies have shown that IL-6 is required for mice to resist Streptococcus pneumoniae infection, suggesting a role for IL-6 in fighting infection.IL-6 promotes inflammatory and autoimmune disease processes in many diseases such as diabetes, atherosclerosis, depression, Alzheimer’s disease, systemic lupus erythematosus, multiple myeloma, prostate cancer, leukemia, and rheumatoid arthritis. Patients with advanced/metastatic cancer have high levels of IL-6 in their blood.