NLRP3 inflammasome is activated in two steps: the first signal (signal 1) indicating infection or tissue damage includes toll-like receptor 4, a pattern recognition receptor that can recognize lipopolysaccharide (LPS) and a series of endogenous risk signals, which activate nuclear factor kappa B (NF-κB) to increase the protein expression of NLRP3, pro-IL-1β, and pro-IL-18. The gene discussed is NLRP3; the disease is infection.