Interleukin-1 is a key mediator of inflammation, with pleiotropic effects on several cells and signaling pathways. The activity defined as IL-1 reflects the function of 2 molecules, IL-1alpha and IL-1beta. IL1A encodes IL-1alpha, which is cell-bound, and IL1B encodes IL-1beta, a secreted cytokine (1). IL-1alpha and IL-1beta are synthesized as 31-kD precursors and are processed by proteases to their mature 17-kD forms. IL-1beta-converting enzyme cleaves the inactive IL-1beta Precursor and ProIL-1alpha is processed by calpain (4). IL-1beta is a tumor-promoting cytokine, and it enhances tumor metastasis and angiogenesis. IL-1beta is able to facilitate tumor progression in murine models of lung cancer. Upregulation of metastasis and tumor angiogenesis by IL-1beta has been associated with increased activity of matrix metalloproteinases and expression of the pro-angiogenic molecule hepatocyte growth factor (5).