SIGIRR and necrotizing enterocolitis: No change was observed across experimental groups for IL-10 (Fig. 3e), whereas Il1rn (protein name IL-1Ra) was 80% reduced by IL-37 in NEC pups (jejunum only, Supplementary Fig. 3f), and Sigirr (protein name IL-1R8) was twofold increased in IL-37tg at steady state but not in NEC (Fig. 3f).