Jack has extensive experience in the general representation of associations, antitrust counseling, health care regulatory issues, copyright, trademark and trade secret matters, and FDA regulation.

Jack has represented numerous clients in government antitrust and health fraud investigations, in actions brought by the US Department of Justice and the Federal Trade Commission, in private antitrust litigation, and in copyright, trademark, and trade secret cases.

Some of the nation’s leading professional associations turn to Jack for his counsel, including the American Medical Association, American Dental Association, American Optometric Association, National Association of REALTORS®, Federation of State Medical Boards, American Board of Medical Specialties, American Academy of Periodontology, American Association of Endodontists, American Veterinary Medical Association, American Health Information Management Association, and Greater Las Vegas Association of REALTORS®. He also advises several medical and dental certifying boards, such as the American Board of Dermatology, American Board of Emergency Medicine, and American Board of Periodontology. He also represents a number of accreditation organizations, including the Liaison Committee on Medical Education, ARC-PA, and CoARC.

Jack teaches courses on health law and food and drug law at the University of Chicago. He is a frequent speaker on antitrust, association law, and health care regulatory issues at industry and university conferences, and has written many articles on these topics.