U.S. sprinter Erriyon Knighton's doping case, linked to contaminated meat consumption, is being appealed by the Athletics Integrity Unit (AIU) to the Court of Arbitration for Sport. Knighton tested positive for the banned substance trenbolone but was previously cleared by the U.S. Anti-Doping Agency (USADA) due to a ruling of no fault or negligence, asserting the contamination was likely from oxtail purchased from a bakery. Following the decision, Knighton competed at the Paris Olympics, finishing fourth in the men's 200m final. The AIU's appeal challenges the arbitration panel's conclusion, highlighting ongoing tensions between USADA and the World Anti-Doping Agency over handling contamination cases. Concerns about fairness in treatment of U.S. versus Chinese athletes have surfaced amid this dispute, as some argue Knighton may be collateral damage in the larger conflict between anti-doping authorities. USADA acknowledges the AIU's reasons for the appeal, reflecting broader issues in the doping regulations landscape.