STUB1 and cerebellar ataxia: The current notion of STUB1 as causing a relatively circumscribed ‘ataxia plus phenotype’ is remarkable, since CHIP, the protein encoded by STUB1, is a key component of general cellular protein homeostasis [7, 8] and interacts with several proteins involved in the pathogenesis of various neurodegenerative diseases and system degenerations, including Tau, α-Synuclein, Parkin2, LRRK2, Ataxin1, Ataxin3, and ATCAY (for references and overview, see Figure Additional file 1).