Anti-Caspase 1 antibodies are directed against the protein encoded by the gene CASP1 in humans. The Caspase 1 protein has an expected mass of 45.2 kDa, but there are 5 reported isoforms. The protein may also be known as ICE, IL1BC, P45, CASP1 nirs variant 1, and IL-1 beta-converting enzyme. Variants of this antigen may also be found in other species, including plants, porcine, monkey, mice, and rats.