RPS27A and neurodegenerative disease: Ubiquitin dysfunction has been implicated in several diseases, including neurodegenerative diseases [36,37] as well as several types of cancer [38,39,40], and it has been shown that ubiquitin modifies a large fraction of the human proteome, with over 60,000 sites on more than 9000 distinct proteins identified in mammalian cells [41,42,43].