IL1B and familial cold autoinflammatory syndrome: Rilonacept is an IL-1 receptor fusion protein consisting of the Fc portion of human IgG1 and the human IL-1 receptor which traps both IL-1α and IL-1β, and clinically used for familial cold autoinflammatory syndrome (FCAS), Muckle–Wells syndrome (MWS), and recurrent pericarditis (15).