CYP2D6 and Alzheimer disease: A major conclusion from the results obtained in the present study would be that the influence of SIRT2 in AD pathogenesis and in AD-related genophenotypes is very mild; however, the interaction of SIRT2 variants with other genes (i.e., APOE, CYP2D6) may be relevant, affecting age at onset, clinical course, rate of cognitive decline, and pharmacoepigenetic outcome.