district court
(c) In any suit, action, or proceeding brought under the provisions of this section subpenas for witnesses who are required to attend a court of the United States in any district may run into any other district. However, no writ of subpena shall issue for witnesses living out of the district in which the court is held at a greater distance than one hundred miles from the place of holding the same without the permission of the court being first had upon proper application and cause shown. The word “district” and the words “district court” as used in this section shall be construed to include the District of Columbia and the United States District Court for the District of Columbia.