The study was in real, living mice. From the study text:
> The experimental design employed clinically relevant dosing regimens: E. americana was administered as a single intravenous injection via tail vein at a dose of 200 μL (5 × 10⁹ CFU/mL), while anti-PD-L1 and DOX were administered intravenously every other day for four total injections at 2.5 mg/kg, representing standard therapeutic protocols.
> The experimental design employed clinically relevant dosing regimens: E. americana was administered as a single intravenous injection via tail vein at a dose of 200 μL (5 × 10⁹ CFU/mL), while anti-PD-L1 and DOX were administered intravenously every other day for four total injections at 2.5 mg/kg, representing standard therapeutic protocols.