Besides being an immune protein, IL-6 is also a pyrogen and is responsible for fever in autoimmune, infectious, or non-infectious diseases. IL-6 is produced in the body, wherever there is inflammation, either acute or chronic. This includes situations such as trauma, burns, cancers, and infection. This chemical interacts with interleukin-6 receptor alpha, to induce transcription of inflammatory gene products.

IL-6 is implicated in a host of chronic disease conditions associated with inflammation. Interleukin-6 is also suspected to cause increased susceptibility to diabetes mellitus, as well as to the systemic form of juvenile rheumatoid arthritis.

IL-6 is released by monocytes and macrophages in response to other inflammatory cytokines which include IL-11 and tumor necrosis factor (TNF)-beta. The IL-6 receptor is present on normal T-lymphocytes in the resting phase, normally activated B-cells, and cells in the myeloid and hepatic cell lines. IL-6 is also found on B cells modified by the Epstein-Barr virus.