NLRP3 contains a NACHT/NOD domain that in related proteins is responsible for oligomerization (Inohara & Nunez 2001, 2003). NLRP1 forms oligomers upon stimulation with MDP (Faustin et al. 2007) and the enforced oligomerization of NLRP3 PYD domains enhances ASC-dependent effects on apoptosis (Dowds et al. 2002). NOD-mediated oligomerization is widely considered to be part of the activation process for the NLRP3 inflammasome (Schroder et al. 2010, Schroder & Tschopp, 2010). The extent of oligomerization is not known, but models based on the the apoptotic initiator protein Apaf-1 suggest a posible heptameric platform (Proell et al. 2008).