The patient, the physician, and the regulator.
D002986:Clinical Trials as Topic; D004992:Ethics, Medical; D006808:Humanism; D006801:Humans; D010819:Physician's Role; D010817:Physician-Patient Relations; D011787:Quality of Health Care / Q000331:legislation & jurisprudence*; D012306:Risk; D012380:Role; D014481:United States; D014486:United States Food and Drug Administration