NLRP1 and metabolic syndrome: Overall, these findings suggest that the NLRP1-Caspase-1-IL-18 axis represents an important metabolic rheostat, and that the elevated IL-18 levels observed in the metabolic syndrome, obese people or type 2 diabetes (Fischer et al., 2005; Hung et al., 2005; Zirlik et al., 2007) may result from an attempt to counteract metabolic dysfunction and insulin resistance.