In contrast, the reduced expression level of CDR1as in the brains of AD patients may be due to the fact that microRNA miR-671 has a binding site that is almost completely complementary to CDR1as and induces cleavage of CDR1as by Argonaute 2 (AGO2) protein, which may be one of the important pathways for the reduced expression level of CDR1as in the brains of AD patients [17,19]. This evidence concerns the gene AGO2 and Alzheimer disease.