Although it is not clear whether HAP1 might also protect neurons from TBP-mediated neuropathology, it is intriguing that, despite ubiquitous expression of TBP in all cells of the body, most regions of the brain exhibiting high levels of HAP1 and abundant STBs do not exhibit neuropathology in SCA17 patients [4-6,20,23,29]. Here, HAP1 is linked to spinocerebellar ataxia type 17.