The Gregors (played by Dana Gladstone) were Human-Alien hybrids cloned after two hybrids originally created by the colonists. These original visitors had come to Earth in the 1940's in order to have a part in colonization. The Gregors' plan and actions were not sanctioned, but they still pursued hybridization experiments using human fetuses obtained in abortion clinics where they worked. These clinics were scattered around the United States. The Gregors participated in the creation of a Samantha Mulder clone series and these female hybrids, who considered the Gregors their fathers, became their partners on this project. Two of their cloning facilities were situated in a warehouse at 3243 Edmonton, Germantown, Maryland as well as at Women's Health Services Clinic in Rockville, Maryland. An alien bounty hunter was sent by the colonists to eliminate them and put an end to their work.