ATXN2 and neoplasm: Such purification efforts would be cumbersome in view of the limited expression of both proteins in tumor cell lines and the 140 kDa size of ATXN2, and it might be impossible to model the complex effects of all splicing variants of PARK2 [74] and of the stress-triggered redistribution from the cytoplasm to stress granules in the case of ATXN2 and from the cytoplasm to mitochondria in the case of PARK2.