Centre de Recherche en Cancérologie de Marseille, Laboratoire d'Oncologie Moléculaire, UMR891 Inserm, Institut Paoli-Calmettes, Université de la Méditerranée, 13009 Marseille, France.
Breast cancers differ in many ways, such as in their cell of origin, the molecular alterations causing them and the susceptibility and defenses of the patient, and this makes it difficult to give the most appropriate treatment. Two recent papers have contributed to the establishment of a more precise molecular classification of breast tumors.