In agreement with this hypothesis, and as found also for some Alzheimer’s disease cases, specific staining with anti-tau 3R or 4R antibodies resulted negative [28], suggesting tau inclusions in this case could be immature, masking the specific epitopes for the two isoforms tested and precluding conclusions on the main isoforms constituting the aggregates. Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.