This approach is currently followed with an AAV1-based gene therapy trial to increase expression of Progranulin in patients with frontotemporal dementia with granulin mutations [120] (Press release January 28th 2021: Passage Bio—Passage Bio Receives FDA Clearance of IND Application for PBFT02 Gene Therapy Candidate for Treatment of Patients with Frontotemporal Dementia with Granulin Mutations). Here, GRN is linked to frontotemporal dementia.