805 ILCS 10/6
One or more individuals each of whom is licensed to perform the same professional service or related professional services in this State may organize a professional corporation by filing articles of incorporation with the Secretary of State on forms furnished by the Secretary. Such articles of incorporation shall meet the requirements of the "Business Corporation Act of 1983" and in addition thereto state the specific profession or related professions to be practiced by the professional corporation.
A professional corporation may be organized under this Act only for the purpose of rendering one specific type of professional service and services ancillary thereto; provided, however, that nothing herein shall be construed to prevent a professional corporation from organizing under this Act where that corporation is organized for the purpose of rendering related professional services and services ancillary thereto; and provided, however, that nothing herein shall prohibit an attorney licensed to practice law in Illinois from signing and acting as initial incorporator on behalf of such corporation.
805 ILCS 10/6