Michael J. Fox opened up to ET at the 25th Annual A Funny Thing Happened on the Way to Cure Parkinson’s Gala about what drives his “great mission” to help others with Parkinson's. “It's about people and their families that are struggling with this disease and want an answer," he told ET at the event, which raised over $4.3 million for Parkinson’s research. The actor, who was joined by his four children with wife Tracy as well as many of his famous friends, left us with this piece of advice, "Be

Actor Chris Hemsworth is opening up about his father's battle with Alzheimer's and his own heightened risk of developing the disease. James Longman reports on their road trip together and what they're hoping to learn together. https://abcnews.go.com/ | ABC World News Tonight with David Muir