What we learned this week in the trial of Elizabeth Holmes

The trial of Theranos founder Elizabeth Holmes concluded its fourth week on Friday, with the lengthiest witness testimony of the trial so far.

That testimony has come from former Theranos lab director Adam Rosendorff, who has been on the stand for four days and will continue his testimony Tuesday. Rosendorff said on the stand that he "felt pressured to vouch for tests that I did not have confidence in" and that he "felt obligated from a moral and ethical perspective" to tell the public what was happening at the company.

The defense has argued that the accuracy and reliability of the company's tests were not Holmes' responsibility, and that the legal responsibility fell to those running the lab.