In a special "20/20" event, ABC News reports on the latest chapter in the downfall of Elizabeth Holmes and her blood-testing company Theranos, once valued at $9 billion.
Barbara Walters, Chris Connelly, Christopher Chacon, Diane Sawyer, Elizabeth Vargas, Fantasia Barrino, Geraldo Rivera, Hugh Downs, Liza Minnelli, Mariah Carey, Patty Duke
Documentary