In University of California v. Broad Institute, Inc. the Fed. Cir. affirmed the PTAB’s determination of “no interference-in-fact” as their factual findings of no expectation of success were supported by substantial evidence.  In accessing the obviousness of Broad’s method of altering expression in a eukaryotic cell by introducing a CRISPR-Cas system, in view of UC’s claims to a method a nucleic acid cleavage method using a CRISPR Cas system, based on demonstration in a non-cellular experimental environment, the Fed. Cir. found the Board’s conclusion to be supported by substantial evidence, including Broad’s expert’s testimony that application in eukaryotic cells is unpredictable, UC’s expert’s publication that success in eukaryotes “remains to be seen” and UC’s inventor’s statement that she had “many frustrations” in getting CRISPR-Cas9 to work in human cells and that success would be “a profound discovery.”  The Fed. Cir. noted that while there was substantial evidence that there would have been a reasonable expectation of success of implementing the CRISPR-Cas9 in eukaryotes, the role of the appellate court is not to reweigh the evidence.