Cognitive impairment in DLB and PDD have been associated with CSF AD biomarkers (tau phosphorylated at threonine 181 [P‐tau181], total tau and Aβ42),10 and tau‐PET measures.11, 12 However, limited availability, cost, and invasiveness hamper global implementation in identifying AD pathology in clinical settings and clinical trials. This evidence concerns the gene MAPT and Cognitive impairment.