NALP proteins, such as NALP2, are characterized by an N-terminal pyrin (MIM 608107) domain (PYD) and are involved in the activation of caspase-1 (CASP1; MIM 147678) by Toll-like receptors (see TLR4; MIM 603030). They may also be involved in protein complexes that activate proinflammatory caspases (Tschopp et al., 2003 [PubMed 12563287]).[supplied by OMIM, Mar 2008].