Journal of Clinical Medicine Article The New Synthetic Serum-Free Medium OptiPASS Promotes High Proliferation and Drug Efficacy Prediction on Spheroids from MDA-MB-231 and SUM1315 Triple-Negative Breast Cancer Cell Lines Clémence Dubois 1,2, Pierre Daumar 1 , Corinne Aubel 3, Jean Gauthier 4, ...