Caspase-12 is a member of the ICE/CED-3 family of caspases and is detected as a protein of ~51 kDa. Overexpression of caspase-12 in cells induces apoptosis. Capase-12 is localized to the endoplasmatic reticulum (ER) and activated by ER stress and specifically cleaves and activates pro-caspase-9 and is also thought to be involved in the apoptosis induced by viral infection. Caspase-12-deficient mice are resistant to ER stress-induced apoptosis. Caspase-12 is probably expressed in many and perhaps all mouse tissues and is expressed at high levels in skeletal muscle, heart, lung and kidney and at moderate levels in brain and liver. In many humans caspase-12 is a pseudo gene and not expressed.