Ataxin 1 (ATXN1), the protein that causes spinocerebellar ataxia type 1, has an ataxin-1 and HMG-box protein 1 (AXH) sequence, which was initially discovered in the high-mobility group transcription activator HMG1, gave the first evidence tying ATXN1 to transcription. Here, ATXN1 is linked to spinocerebellar ataxia type 1.