Cell death via apoptosis is a key cellular function triggered by the cell death receptor family and their ligands. This regulated process then transmits downstream signals through adaptor molecules ending with the caspase cysteine proteases. Caspase 11 has a heterotetrameric structure consisting of two anti-parallel heterodimers. Upon activation, it is cleaved by an autocatalytic mechanism to give rise to individual subunits. This post-translational regulation enables rapid activation. Expression levels of caspase 11 are highest in lung and spleen.