We had elucidated the signaling pathways by which COX-2 mediates the effects in which IL-1β induced the expression of BACE-1 in neuron cells, and BACE-1 is the key enzyme for the synthesis and accumulation of Aβ (Cai et al., 2001); however, the roles of Aβ in the pathogenesis of AD have not been thoroughly discussed. This evidence concerns the gene PTGS2 and Alzheimer disease.