Elizabeth Holmes, the disgraced founder of Theranos, is appealing her fraud conviction at a federal courthouse in San Francisco on Tuesday. The hearing comes one year after Holmes began serving an 11-year sentence for defrauding investors. Holmes' attorneys are questioning the testimony of a former lab director, a key witness for the prosecution. They are urging the federal appeals court to grant a new trial. The appeal also includes Ramesh 'Sunny' Balwani, the former president of Theranos, who was convicted alongside Holmes. The company, once valued at $9 billion, collapsed after its blood-testing technology was exposed as fraudulent. Lawyers describe the appeal as a 'long-shot.'