Inflammatory symptoms of Cryopyrin-Associated Periodic Syndrome (CAPS) are due to mutations in a the NLRP-3 gene (previously known as Cold Induced Autoinflammatory Syndrome-1 or CIAS1). These mutations result in the body's overproduction of interleukin-1 (IL-1), a protein that stimulates the inflammatory process. IL-1 Trap (rilonacept) was designed to bind to the interleukin-1 cytokine and prevent it from binding to its receptors in the body.