CRISPR patents continue to face priority challenges in Europe. Following an earlier revocation of CRISPR patent EP2771468 based on a successful priority challenge, another foundational CRISPR patent EP3241902, co-owned by University of California Berkeley (UCB), was revoked in its entirety last month by the European Patent Office (EPO) based on an invalid priority claim. This is the first significant loss of UCB’s CRISPR patent rights in Europe.