Interleukin-1 beta (IL-1β) is a proinflammatory cytokine that is mainly produced by monocytes and activated macrophages as a proprotein. Inflammatory responses are mediated by IL-1β in T cells, natural killer cells (NK cells) and B cells. It induces the production of pro-inflammatory cytokines (IL-2, IL-3, IL-6) as well as interferons. Furthermore, IL-1β modulates the secretion of cytokines by various subsets of human DCs.