Caspase recruitment domain-containing protein 8 is an enzyme that in humans is encoded by the CARD8 gene.

The protein encoded by this gene belongs to the caspase recruitment domain (CARD)-containing family of proteins, which are involved in pathways leading to activation of caspases or nuclear factor kappa-B (NFKB). This protein may be a component of the inflammasome, a protein complex that plays a role in the activation of proinflammatory caspases. It is thought that this protein acts as an adaptor molecule that negatively regulates NFKB activation, CASP1-dependent IL1B secretion, and apoptosis. Polymorphisms in this gene may be associated with a susceptibility to rheumatoid arthritis. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, May 2010].
Function: Inhibits NF-kappa-B activation. May participate in a regulatory mechanism that coordinates cellular responses controlled by NF-kappa-B transcription factor. May be a component of the inflammasome, a protein complex which also includes PYCARD, NALP2 and CASP1 and whose function would be the activation of proinflammatory caspases.