STUB1 and autosomal recessive cerebellar ataxia: At this point, the only available animal model to study CHIP function is the mouse in which the entire STUB1 gene has been deleted.11,17 Although it is difficult to say at this time how mutations within the TRP, charged, or U-box domains specifically affect the symptoms associated with ARCA, the development of animal models with isolated domain mutations may help identify how the bifunctional roles of CHIP affect clinical pathologies.