Transcriptional dysregulation and mitochondrial dysfunction are interconnected processes in HD governed by the crosstalk between p53 and the mitochondrial biogenesis factor PGC-1α (peroxisome proliferator-activated receptor γ co-activator 1α; Steffan et al., 2000; Jin and Johnson, 2010). The gene discussed is PPARGC1A; the disease is Huntington disease.