Erika Cheung, who took the stand yesterday for her direct testimony, which continued today, is known for being one of John Carreyrou’s sources for his blockbuster article about Theranos. You know, the article that’s part of the reason we are now witnessing US v. Elizabeth Holmes. (Holmes is on trial for several counts of wire fraud and conspiracy to commit wire fraud.)
Cheung is, famously, one of the people who blew the whistle on Holmes. She’s even given a TED talk about it. The other major source for Carreyrou was her friend, Tyler Shultz, who also worked at Theranos and was the grandson of one of the board members. He is expected to testify later in the trial, since he tried to bring problems in the lab to Holmes’ attention.
At Theranos there were two labs, Cheung testified: the research and development lab and the clinical lab. She worked in both, starting with the R&D lab. Her position in both labs was largely the same — an entry-level job that involved running quality control tests to make sure the machines were working properly. About a quarter of the Theranos machines failed the test at any given time, Cheung said. By comparison, the commercially available machines failed much less frequently.