Alzheimer's disease (AD), in which energy supply is impaired, affects actin and microtubule turnover.79,80 Cofilin, an actin-binding protein, may link cytoskeletal aberrations to mitochondrial impairments characteristic not only of AD, but also of related pathologies such as Parkinson's and Huntington's disease.81 Understanding how non-signalling processes contribute to the brain's energy budget is therefore important. The gene discussed is CFL1; the disease is juvenile Huntington disease.