Ubiquitous activation recapitulates SCA1-like PC pathology (dendritic atrophy, inclusions) but delayed. Cell-specific contributions toward respiratory failure; Crossing with various Cre lines cleanly separates contributions of neuronal subtypes (e.g., showing Purkinje neurons are necessary for major pathology, motor neurons contribute little to lifespan); An ideal platform to test gene-silencing. Here, ATXN1 is linked to respiratory failure.