A petitioner may challenge an issued patent in an inter partes review (IPR) before the Patent Trial and Appeal Board, an agency tribunal, but "only on the basis of prior art consisting of patents or printed publi-cations." 35 U.S.C. § 311(b). The Federal Circuit reviews the Board's decisions under the standards set out in the Administrative Procedure Act.

The questions presented are:

1. Whether the Federal Circuit's practice of allowing IPR petitioners to rely on evidence other than pa-tents and printed pub lications, such as expert testimony, to fill in gaps in the prior art violates the plain text of § 311(b).

2. Whether the Federal Circuit's practice of resolving contested issues of patentability on appeal from Board decisions —rather than remanding those issues for the agency to decide in the first instance—violates the "ordinary remand rule."

Whether the Federal Circuit's practice of allowing IPR petitioners to rely on evidence other than patents and printed publications to fill in gaps in the prior art violates the plain text of § 311(b)