CASP1 and Arthritis: Indeed, mice lacking the inflammasome adaptor protein apoptosis-associated speck-like protein containing a CARD (Asc) but not Nlrp3 or caspase-1 mice were protected from collagen-induced arthritis and antigen-induced arthritis [51, 52] whereas NLRP3 and IL-1 receptor type 1 (IL-1R1) were important for the pathogenesis of arthritis induced by A20 ablation [53].