While many subjects may show concordance in the long term [42], more work is required to integrate and compare CSF analysis and amyloid PET so as to develop more refined guidelines for how these biomarkers are to be used and interpreted in the diagnostic work-up of patients with dementia disorders [43], including considerations related to differences in amyloid processing and neurodegeneration seen across atypical forms of AD [44] and the value of Aβ1-42 ratios with shorter isoforms [45, 46] and tau/Aβ1-42 [47]. The gene discussed is MAPT; the disease is Alzheimer disease.