IL-1 beta (interleukin 1 beta) belongs to the interleukin family and is a potent proinflammatory cytokine. Originally discovered as the most important endogenous pyrogen, IL-1 beta induces prostaglandin synthesis, neutrophil influx and activation, T-cell activation, cytokine production, B-cell activation, antibody production, as well as fibroblast proliferation and collagen production. IL-1 beta plays a role in angiogenesis by inducing VEGF production synergistically with TNF and IL6.