STAT1 and Ataxia-telangiectasia: Given that IFNs upregulate transcriptional gene expression of ISGs41 and that upregulation of IFNβ was observed in another type of cerebellar degeneration, Ataxia-Telangiectasia (A-T)38, we examined developmental changes of the IFNβ protein level and STAT1 phosphorylation at Tyr701 (Fig. 6d).