The United States filed a complaint under the False Claims Act against Yury Gampel, a chiropractor, 15 Modern Vascular office-based labs located throughout the United States primarily owned by Gampel, and five Modern Vascular-affiliated companies owned by Gampel, for engaging in allegedly illegal financial relationships and transactions. Office-based labs, such as the ones named as defendants here, are an extension of a physician's office where physicians conduct examinations and procedures on an ambulatory basis.