A recent study reported that Ft-specific IgM produced by B1a B cells was significantly reduced in Il-1b/-, Il-1b-/-/Il-1a-/-, or Il-1r1-/- mice compared to C57BL/6J wildtype or Il-1a-/- mice and implicated as an explanation for susceptibility of IL-1β-deficient mice to pulmonary Ft LVS infection [13]. Here, IL1R1 is linked to infection.