This gene encodes a member of the cysteine proteases that plays important roles in apoptosis, cell migration and the inflammatory response. The encoded protein mediates production of pro-inflammatory cytokines by macrophages upon bacterial infection. Mice lacking the encoded protein are resistant to endotoxic shock induced by lipopolysaccharide. A 5-bp deletion encompassing a splice acceptor junction resulting in alternate splicing and a shorter non-functional isoform in certain mouse strains has been described. Although its official nomenclature is 'caspase 4, apoptosis-related cysteine peptidase', this gene and its encoded protein have historically been called caspase 11. This gene is present in a cluster of three caspase genes on chromosome 9.