SQSTM1 and fragile X-associated tremor/ataxia syndrome: In this regard, nearly 200 different proteins enriched in FXTAS inclusions have been recently identified, being the small ubiquitin-related modifier 2 (SUMO2), ubiquitin and p62/sequestosome-1 (p62/SQSTM1; hereafter designated p62), the most highly abundant ones [11].