Chakrabarty (plaintiff) filed a patent application for a human-made microorganism. A patent examiner rejected the patent because it was outside of the scope of patentable subject matter under 35 U.S.C. §101. The Patent Office Board of Appeals affirmed and ruled that living things are not patentable subject matter under § 101. The Court of Customs and Patent Appeals reversed. Diamond (defendant), the Commissioner of Patents, petitioned the United States Supreme Court for certiorari. Diamond argued that, by enacting the Plant Variety Patent Act, Congress implicitly understood that living things were not within the scope of 35 U.S.C. §101. Diamond also argued that the Court should show restraint in expanding 35 U.S.C. §101 under Parker v. Flook, 437 U.S. 584 (1978), which urged Courts to show caution before expanding protection under 35 U.S.C. §101 into new, unforeseen areas. The United State Supreme Court granted certiorari.