20 ILCS 2505/2505-175

Business in interstate commerce; restricted application of tax statutes. It is the intent of the General Assembly that provisions in any Illinois tax statute that restrict application of the statute by stating substantially as follows:

such taxes are not imposed with respect to any business in interstate commerce, or otherwise to the extent to which such business may not, under the Constitution and statutes of the United States, be made the subject of taxation by this State

shall be construed to preclude taxation of only businesses not subject to taxation under the latest interpretation of the United States Constitution and statutes of the United States.