 Gillibrand's tenure at Davis Polk included serving as a defense attorney for tobacco company Philip Morris during major litigation, including both civil lawsuits and U.S. Justice Department criminal and civil racketeering and perjury probes.As a junior associate in the mid-1990s, Gillibrand defended the company's executives against a criminal investigation into whether they had committed perjury in their testimony before Congress when they claimed that they had no knowledge of a connection between tobacco smoking and cancer.Gillibrand worked closely on the case and became a key part of the defense team.