Genetic mouse models have demonstrated that ablation of HSPs such as HSP70 and HSP60 can cause neurological defects including cerebral ischemia, Huntington's disease and motor neuron disorders.31, 32, 33 Given that it has been previously shown that ablation of PGC1α in vivo is associated with brain abnormalities,18, 19 it is possible that part of the PGC1α-null mice phenotype may be due to decreased levels of HSPs in this organ. The gene discussed is HSPA1A; the disease is juvenile Huntington disease.