Bks is required for Tll function, and so is Atrophin [21], the homolog of human Atrophin-1, which causes the neurodegenerative disease dentatorubral-pallidoluysian atrophy (DRPLA) when a polyglutamine stretch in the protein is expanded (reviewed in [22]). This evidence concerns the gene TLL1 and dentatorubral-pallidoluysian atrophy.