MAPT and Alzheimer disease: The recently revised AD diagnosis and staging criteria of the Alzheimer's Association workgroup incorporated the following BBMs into their framework: core AD BBMs are amyloid beta1‐42/amyloid beta1‐40 (Aβ42/Aβ40) ratio, phosphorylated mid‐region tau (pTau) variants (pTau181, pTau217, pTau231), and pTau/Aβ42 ratio.2