Interleukin-6 (IL-6) is a cytokine, a type of small protein that plays a role in the immune response and inflammation. It is produced by various cells in the body, including immune cells, and is involved in many biological processes, such as regulating the immune system, promoting the growth and differentiation of cells, and regulating inflammation. Research on IL-6 is conducted in various fields, including immunology, oncology, and neurology. Studies on IL-6 have shown its role in various diseases, such as autoimmune disorders, cancer, and inflammatory conditions. Researchers are also investigating the potential therapeutic applications of targeting IL-6 in the treatment of these diseases.