Of particular relevance is the observation that monosodium urate (MSU) crystals induce activation of the NLRP3 inflammasome, a protein complex expressed in macrophages and certain other cell types, which promotes caspase-1-driven release of mature IL-1β, with subsequent induction of numerous downstream inflammatory mediators that contribute to the clinical presentation of the signs and symptoms of gouty arthritis [23]. This evidence concerns the gene IL1B and gout.