The U.S. FDA’s final rule for regulation of lab-developed tests was destined to be controversial at best and exceptionally susceptible to legal challenge according to more than one legal opinion. The inevitable legal challenge succeeded wildly in a decision rendered in district court in March 2025, marking one of the rare instances in which the courts thwarted FDA rulemaking and thus is easily the regulatory story of the year for 2025. Attempts to regulate AI in the U.S. and Europe also dominated the regulatory landscape.