IL1B and aortitis: It was reported that the development of aortitis was diminished in Il1r1−/−Il1rn−/− mice and Tnfa−/−Il1rn−/− mice, whereas it was normal in Il6−/−Il1rn−/− mice21,22, indicating that IL-1α and/or IL-1β, and TNF are crucial for development of aortitis in Il1rn−/− mice.