Since ADAMTS-5 is most prominently expressed in the dendrites of the pyramidal neurons of the hippocampus and its protein levels are dramatically decreased in old 3xTg-AD mice, it is plausible that the acceleration of the Reelin aggregation in striatum radiatum of AD mice is, at least in part, due to the decreased Reelin degradation by ADAMTS-5. This evidence concerns the gene ADAMTS5 and Alzheimer disease.