We examined brains of tau transgenic flies homozygous for the Lrrk mutant allele or expressing either wild-type Lrrk or Lrrk carrying the G1914S mutation (Lrrk-GS), the mutation homologous to the most common Parkinson disease—associated mutation in human LRRK2 (G2019S). The gene discussed is MAPT; the disease is Parkinson disease.