As aforementioned abundant CatB is expressed in neuronal perikarya as well as extracellularly associated within senile plaques in the postmortem brain of AD patients (Cataldo et al. 1990), and lysosomal protease-mediated APP processing in degenerating neurons is considered to develop the plaques (Cataldo and Nixon 1990). The gene discussed is TYRP1; the disease is Alzheimer disease.