In the present study using the ubiquilin class-specific antibodies, focally swollen, dystrophic neurites distributed in the CA1 region and the molecular layer in the hippocampus of both AD and non-AD brains express both UBQLN1 and C9orf72, but they do not express phospho-TDP-43, p62 or UBQLN2, suggesting the possibility that C9orf72 concentrated in dystrophic neurites plays a key role in the homeostasis of protein degradation, by acting in cooperation with UBQLN1. Here, UBQLN2 is linked to Alzheimer disease.