However, it remains unclear whether a decrease in gBOLD–CSF coupling is a cause or a consequence of Aβ accumulation, as those studies may not place much focus on the “AD continuum” principle [23], which describes AD as a continuous process beginning with Aβ deposition, followed by Tau-mediated brain damage, progressing through mild cognitive impairment (MCI) due to AD, and ultimately culminating in AD dementia. This evidence concerns the gene MAPT and Alzheimer disease.