Cast of ER Cast of ER "ER" is an American drama series that aired on NBC from September 19, 1994 until April 2, 2009. The series featured a large ensemble cast that changed dramatically over its long run. The main cast was augmented by a wealth of recurring characters and award-winning guest stars. The original starring cast consisted of Anthony Edwards as Dr. Mark Greene, George Clooney as Dr. Douglas "Doug" Ross, Sherry Stringfield as Dr. Susan Lewis, Noah Wyle as medical student (later Dr.) John Carter, and Eriq La Salle as Dr. Peter Benton. Julianna Margulies guest starred in the pilot as
Returned to unit may also be on compassionate grounds, such as RTU'ing an injured soldier (or other medical conditions). The term "Returned To Unit" ("RTU") is used in the Canadian Forces and the UK. Returned to unit Returned To Unit or RTU refers to a military member being returned to their home base or home unit, either due to their being medically unfit, their requesting to be withdrawn from training, or their being unfit for training or otherwise disorderly. As military members can only be court-martialed at their home base or unit, being RTU'd for misconduct can often be a precursor to further