Retraction Statement.

The article "Post-Progression Treatments after Palbociclib plus Endocrine Therapy in HR+/HER2- Metastatic Breast Cancer Patients: What Is the Better Choice?" [Oncology 2021; https://doi.org/10.1159/000521252] by Alessandra Fabi, Mariangela Ciccarese, Sinome Scagnoli, Michelangelo Russillo, Francesco Schettini, Giuseppe Buono, Vito Lorusso, Katia Cannita, Grazia Arpino, Simonetta Stani, Michela Palleschi, Rosalba Rossello, Giuseppina Sarobba, Agnese Fabbri, Marianna Giampaglia, Patrizia Pellegrini, Vincenzo Adamo, Francesca Morelli, Vittoria Barberi, Gianluigi Ferretti, Giovanna Catania, Simona Pisegna, Francesco Cognetti and Diana Giannarelli has been retracted by the Publisher and the Editor.After peer review, the accepted, unedited manuscript was published online as Early View. The authors did not respond to our requests and communication regarding the production process of their article despite extensive attempts at contact. As the article has not been approved by the authors for publication, we cannot publish the final version. To avoid confusion for readers we are retracting the Early View accepted, unedited manuscript.The authors did not respond to correspondence about the retraction.