Anti-Granzyme B antibodies are directed against the protein encoded by the gene GZMB in humans. The Granzyme B protein has a reported amino acid length of 247 and an expected mass of 27.7 kDa. The protein may also be known as CCPI, C11, CGL-1, CGL1, T-cell serine protease 1-3E, and cathepsin G-like 1. Variants of this antigen may also be found in other species, including canine, porcine, monkey, mouse and rat.