The commonalities among these subtypes of secretases mainly include three points: (1) each subtype of secretase acts on APP as a substrate, but with different cleavage sites and products; (2) each subtype of secretase cleaves Notch receptors; (3) each subtype of secretase is closely related to the progression of cancer and AD, and secretase inhibitors play an important role in the treatment of cancer and AD. The gene discussed is APP; the disease is Alzheimer disease.