The Court of Justice overturned the General Court's judgment and annulled the Commission's decisions regarding the Illumina-Grail merger. The Commission had accepted requests from national competition authorities to examine the proposed concentration, even though it lacked a European dimension and did not meet national thresholds.

Grail LLC and Illumina Inc., both US companies, publicly announced a proposal for Illumina to acquire sole control over Grail in September 2020. The concentration did not trigger notification requirements in the EU or EEA due to the absence of turnover in those regions.

The Commission, following a complaint, invited Member States to request an examination of the merger under the Merger Regulation. Several national competition authorities, led by France, submitted requests based on potential effects on competition and trade between Member States.

The Court of Justice found that the General Court's interpretation of the Merger Regulation allowing national authorities to refer non-European mergers to the Commission was incorrect. It emphasized the importance of clear thresholds for notifying transactions to ensure legal certainty for businesses.