Participates in antiviral signaling. Acts as a negative regulator of MAVS-mediated antiviral responses, through the inhibition of the virus-induced RLH (RIG-like helicase)-MAVS interaction (PubMed:18200010). Has no inhibitory function on NF- Kappa-B and type 1 interferon signaling pathways, but enhances NF- Kappa-B and JUN N-terminal kinase dependent signaling through the production of reactive oxygen species (PubMed:18219313). Interacts with MAVS. Ubiquitously expressed. Strongest expression in mammary gland, heart and muscle. Detected in HeLa, HEK293T, THP-1, HL-60, Raji, and Jurkat cell lines. Belongs to the NLRP family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.