DaTSPECT in nfvPPA patients with normal progranulin and negative CSF AD biomarkers was also significantly reduced compared with lvPPA patients with positive CSF AD biomarkers, suggesting nigrostriatal degeneration does not usually appear in the context of AD pathology resent, but it can appear in the context of FTD pathologies. The gene discussed is GRN; the disease is Alzheimer disease.