From the Document: "S. 440 would prohibit patent owners from asserting that they have tribal sovereign immunity during a variety of proceedings held by the Patent and Trademark Office's (PTO) Patent Trial and Appeal Board (PTAB), including inter partes review (IPR). IPRs are procedures for challenging the validity of a patent. The bill also would prohibit patent owners from asserting tribal sovereign immunity as a defense in any International Trade Commission (ITC) proceedings and certain patent infringement proceedings. CBO [Congressional Budget Office] expects that enacting S. 440 would not affect the federal budget."
Congressional Budget Office: http://www.cbo.gov/