Cathepsin B is an enzymatic protein belonging to the peptidase (or protease) families. In humans, it is coded by the CTSB gene. A wide array of diseases results in elevated levels of cathepsin B, which causes numerous pathological processes including cell death, inflammation, and production of toxic peptides. Focusing on neurological diseases, cathepsin B gene knockout studies in an epileptic rodent model have shown cathepsin B causes a significant amount of the apoptotic cell death that occurs as a result of inducing epilepsy. Mutations in the CTSB gene have been linked to tropical pancreatitis, a form of chronic pancreatitis.