IL1RN and aortitis: Indeed, BALB/c IL1rn−/− mice develop transmural aortitis with a neoangiogenic process, from aortic root to popliteal arteries, mimicking human GCA, affecting half of the mice that are 8 weeks old, 78% of mice at a median age of 147 days in the BALB/c background, and 100% of mice at 200 days in the Sf3 background, and associated with a risk of death resulting from an infarction or ruptured aneurysms [14–17].