HTT and Huntington disease: Recent reports show that mutant huntingtininterferes with transcriptional PPAR-γ coactivator-1α (PGC-1α) causing impairment on its function inHD, suggesting that mutant huntingtin plays a role in the dysregulation ofPGC-1α-mediated transcription and activity,impairing mitochondrial function, and leading to HD pathogenesis [56–58].