IL1B and cystic fibrosis: To assess whether genetic variants in the inflammasome/IL-1RI signalling pathway, and particularly genetic NLRC4 deficiency, are risk factors for specific microbial colonization in CF, we evaluated nine gene variants (four in NLRC4, two in NLRP3, one in IL1B and one in IL1RN) in 284 CF patients (Supplementary Table 1).