In addition abnormal huntingtin interferes with normal ubiquitin-proteosome function and one could readily postulate that downregulation of proteins such as HIP-1 that interact with htt could also lead to abnormal protein aggregation such is seen in many degenerative diseases including Huntington's disease, where it is the htt that is qualitatively abnormal [104]. Here, HIP1 is linked to neurodegenerative disease.