RESEARCH TRIANGLE PARK, N.C.--(BUSINESS WIRE)--Yesterday, the European Patent Office (EPO) revoked previously granted claims of Cellectis’ European Patent No. EP 1485475 during an oral hearing in an opposition proceeding initiated by Precision BioSciences. As a result of the opposition, Cellectis’ previously granted claims to single-chain meganucleases, including those derived from I-CreI, were revoked in their entirety. Claims to hybrid meganucleases were cancelled or severely restricted.