CTSS and early-onset autosomal dominant Alzheimer disease: Among the cysteine proteases, the 11 cathepsins are involved in Alzheimer’s disease and various types of cancer, whereas the caspases are most important for apoptotic processes (Section 3.3) They are often tested with the same HyCoSul libraries as their serine protease counterparts, based on similar specificity and mechanisms as in serine proteases.