4. Michael J. Fox
In 1998, 18 years after the final installment of the Back to the Future trilogy was released, Michael J. Fox, the star of the movie, announced that he had Parkinson’s disease, a debilitating condition that affects the nervous system. Since then, he has worked endlessly to support the discovery of a cure for the disease. He even spoke before the Senate Appropriations Committee in 1998 without taking his medication to control his involuntary trembling.