Interleukin-1 (IL-1) is a type of cytokine, which are proteins that play a crucial role in the immune system. It is produced mainly by macrophages and is involved in various inflammatory responses. IL-1 helps to regulate immune cell activity, promoting inflammation to fight infections and heal injuries. There are two main forms of interleukin-1: IL-1α and IL-1β. Both forms bind to the same receptor and trigger similar biological effects, such as fever and the activation of other immune cells. Dysregulation of IL-1 can contribute to various diseases, including autoimmune disorders and chronic inflammatory conditions.