In a decision that provides guidance on a previously "ill-defined" and "nebulous aspect of our federal courts' jurisdiction," the U.S. Court of Appeals for the Tenth Circuit clarified the cases in which federal courts may exercise ancillary enforcement jurisdiction and which law applies—10th Circuit Spotlightstate, federal, or both—when evaluating a plaintiff's standing to bring such a case. Atlas Biologicals v. Kutrubes, No. 20-1401, 2022 U.S. App. LEXIS 28203, — F.4th — (10th Cir. Oct. 11, 2022).