These results suggest the potential use of p-tau181 as first line of testing to identify patients likely to be tau-positive when tested by PET or CSF biomarkers, either to distinguish AD from other non-AD neurodegenerative diseases in cases with mild to moderate dementia or predict future development of AD in cases with MCI (Janelidze et al., 2020). This evidence concerns the gene MAPT and Alzheimer disease.