; and (B) under the authority, direction, and control of the Director while serving in such position. (3) Regional hubs (A) In general Each region under paragraph (1) shall include a major military medical center designated by the Director to serve as the regional hub for the provision of specialized medical services in such region. (B) Capabilities A major medical center may not be designated as a regional hub unless the center— (i) includes one or more large graduate medical education training platforms