MAPT and Alzheimer disease: Given the complexity of molecular pathology of AD and related tauopathies, a diverse set of tau substrate constructs will provide a versatile toolbox for selective detection of AD and other tauopathies in diagnosis, differentiation, and disease course prognostication using ultrasensitive detection technologies such as RT-QuIC and protein misfolding cyclic amplification (PMCA) (Saá et al., 2005; Shahnawaz et al., 2020).