EPA research has also been suppressed by career managers. Supervisors at EPA's National Center for Environmental Assessment required several paragraphs to be deleted from a peer-reviewed journal article about EPA's integrated risk information system, which led two co-authors to have their names removed from the publication, and the corresponding author, Ching-Hung Hsu, to leave EPA "because of the draconian restrictions placed on publishing". EPA subjects employees who author scientific papers to prior restraint, even if those papers are written on personal time.