Section 3-109 - Subpoenas(a) On the request of a party to a proceeding in which a hearing is required or held, the Commission shall issue subpoenas to compel the attendance and testimony of witnesses and the production of documents at a hearing or deposition to be taken by the party.(b) On its own motion, the Commission may issue a subpoena to compel the attendance and testimony of witnesses and the production of documents at a hearing or deposition to be taken by the Commission.(c) A subpoena shall be signed and issued by a commissioner or the Executive Secretary of the Commission.(d)(1) The Commission may exercise the full authority set forth in 42 U.S.C. § 16453(a) through (c) as if set forth in this article.(2) Nothing in the grant of authority set forth in paragraph (1) of this subsection may be construed to preempt or limit any other authority of the Commission under this article.(3) In addition to the authority granted to the Commission under federal law to enforce the provisions of 42 U.S.C. § 16453, the circuit courts of the State have jurisdiction to enforce compliance with this subsection.