TAF4 and Huntington disease: PGC-1α is downregulated by mHtt through interference with the CREB/TAF4-dependent transcriptional pathway.3 More recently, fragmented mitochondria were linked to HD,4 due to increased dynamin-related protein 1 (DRP1) activity.5, 6 The accumulation of mitochondrial damages in postmitotic neurons is therefore considered as a key process in HD pathogenesis.