Notably, the SNP-associated differential effect on IL-1β was seen only at the protein level: tissue mRNA expression of IL-1β on day 1 of CDI was similar in QQ and RR mice (Supplementary Figure 3A) but IL-1β protein was higher in both tissue lysates and in plasma of C. difficile-infected RR mice. The gene discussed is IL1B; the disease is clostridium difficile infection.