In both AD and cognitively unimpaired individuals, positron emission tomography (PET) and cerebrospinal fluid (CSF) studies find NPSs to be associated with amyloid beta (Aβ) and tau pathologies, supporting an etiological role for ADNC in the development of these symptoms, although results are variable.33, 34, 35, 36, 37, 38, 39, 40, 41. This evidence concerns the gene MAPT and Alzheimer disease.