On Friday, January 8, 2021, the U.S. Supreme Court granted a writ of certiorari filed by Minerva Surgical Inc. in a dispute with Hologic Inc. The question presented by Minerva is “whether a defendant in a patent infringement action who assigned the patent, or is in privity with an assignor of the patent, may have a defense of invalidity heard on the merits.” The U.S. Supreme Court took no action on a cross-petition from Hologic, which argued that assignor estoppel should apply not only in district court, but also in inter partes reviews at the Patent Trial and Appeal Board (PTAB).