Importantly, reduced cerebellar size correlated with behavioral deficits in Tg (Atoh1-Cre +);Brd4fl/fl mice, which exhibited symptoms of cerebellar ataxia not evident in Tg (Atoh1-Cre−);Brd4fl/fl mice (Fig. 6c; Supplementary Movies 1–3). The gene discussed is ATOH1; the disease is cerebellar ataxia.