The results of this study revealed a compromise transport activity of ABCB1 and suggested that ABCB1 downregulation might contribute to the progression of Aβ deposition in the brain; they observed a 23% increase in binding potential of [11C]-verapamil in the cortical region and higher binding potentials in other smaller brain regions of AD patients [38]. This evidence concerns the gene ABCB1 and Alzheimer disease.