To our knowledge, this is the first study demonstrating in a comprehensive manner that genistein stimulates autophagy through the FOXO3-related mechanism, thus, reducing levels of mHTT in the brains and correcting behavior of the HD mice as assessed in a battery of cognitive, anxious and motoric tests, even if administered after the animals have developed symptoms, and at the same time abolishing oxidative stress, inflammation, and stress responses. The gene discussed is FOXO3; the disease is Huntington disease.