IL1B and infection: Here, mice singly deficient for IL-1α or IL-1β survived the acute phase of infection without bodyweight loss, while mice deficient for both IL-1α and IL-1β, similar to IL-1R1 deficient mice, rapidly lost weight and succumbed within 5 weeks of infection with M. tuberculosis H37Rv, that is, 1 week after TNF deficient mice (Fig. 2A,B).