The adviser declined to confirm whether Warren would be Biden’s explicit target. But with her polling in second place in many state and national polls, the former vice president’s team is paying close attention to her.

While Warren has posted tax returns dating back to 2008 on her campaign website, the Biden camp appears to be calling for greater scrutiny of the years before 2008, the year she was appointed to the Congressional Oversight Panel that examined the government response to the financial crisis.

Warren, whose presidential effort is styled around fighting corporate America, has taken on corporate clients as an adviser or expert witness on bankruptcy in the last 20 years. In May, her campaign posted brief descriptions of her roles in those cases and some of that work has been questioned during her two Senate campaigns in Massachusetts.