This gene encodes an adaptor protein that is composed of two protein-protein interaction domains: a N-terminal PYRIN-PAAD-DAPIN domain (PYD) and a C-terminal caspase-recruitment domain (CARD). The PYD and CARD domains are members of the six-helix bundle death domain-fold superfamily that mediates assembly of large signaling complexes in the inflammatory and apoptotic signaling pathways via the activation of caspase. In normal cells，this protein is localized to the cytoplasm; however，in cells undergoing apoptosis，it forms ball-like aggregates near the nuclear periphery. Two transcript variants encoding different isoforms have been found for this gene.