NLRP3, also known as NALP3, CIAS1, PYPAF or Cryopyrin, is a cytosolic ~120 kDa member of the NLRP family of proteins expressed in leukocytes, especially neutrophils. As a component of the inflammasome, NLRP3 activates caspases 1 and 5. Defects in NLRP3 may cause FCAS1, CINCA, or Muckle-Wells autoinflammatory syndromes. Mouse NLRP3 contains an N-terminal Pyrin domain (aa 1-91) followed by a Nacht region (aa 216-532), and seven LRRs (aa 739-988). Within the sequence used as an immunogen, mouse NLRP3 shares 78% and 93% aa identity with human and rat NLRP3, respectively. Alternate splicing of mouse NLRP3 generates additional isoforms that lack either LRR2 and 3, LRR 6 and 7, or LRR4-9.