By contrast, t‐tau has not yet exhibited prognostic potential in premanifest HD, but further investigation is supported by the fact that CSF tau levels correlate with clinical features in manifest HD [7], tau pathology is over‐represented in post‐mortem HD brains [11, 12, 13], and tau immunisation has been found to improve clinical outcomes in HD mouse models [14]. The gene discussed is MAPT; the disease is Huntington disease.