A frameshift mutation in the ubB (ubiquitin) gene (UBB+1) selectively expressed in brain was associated with increases in neurofibrillary tangles and plaques in AD, Pick’s disease and Down’s syndrome patients, but was not found in the healthy young population, which suggests a link between the UPS and AD pathogenesis (van Leeuwen et al., 1998, 2006). This evidence concerns the gene UBB and Alzheimer disease.