To tease apart the functional contributions of caspase-1 versus caspase-11 during LPS-induced endotoxemia, Kayagaki et al.microinjected a caspase-11 bacterial artificial chromosome (BAC) transgene into the Casp1-/-Casp11-/- DKO embryo to generate mice lacking just caspase-1 (Casp1-/-Casp11Tg mice) [104]. Here, CASP1 is linked to serum lipopolysaccharide activity.