The recent European Court of Justice victory for TowerCast has reverberated around the European Union, with the court’s decision suggesting a path for regulators to deal with so-called killer acquisitions. The court sided with an interpretation confirming that a prohibition on abuse of a dominant position is an acceptable avenue for officials wanting to block deals that involve established companies buying startups to shut down any risk of future competition. The decision is now casting a shadow over Illumina’s jurisdictional appeal for its acquisition of Grail — an acquisition that has been vetoed by the European Commission.