James Wilson is the oncology specialist and House’s best friend in House M.D.
Robert Sean Leonard played Wilson throughout the series. Wilson’s medical specialty is oncology, the branch of medicine concerned with cancer. His work made him a recurring source of information about cancer treatment and the emotional realities faced by patients and families.
Wilson acts as a moral and emotional counterweight to Gregory House. Although he often disapproves of House’s behavior, he repeatedly helps him and understands parts of his personality that other colleagues do not. Their friendship is one of the series’ central long-running relationships.
Wilson is sometimes mistaken for House’s professional supervisor or for the hospital administrator. Lisa Cuddy held the major administrative role, while Wilson primarily served as an oncologist, colleague, and close friend.