AuthOr’s VIew AuthOr’s VIew

Breast cancers are the most common malignant tumors and the first leading cause of cancer-related deaths in women. Among several types of breast carcinoma, the so-called triple negative (TN)—that is, HER2/neu−, estrogen receptor − and progesterone receptor − is generally viewed as the most aggressive one. Breast cancers are considered immunogenic tumors as CD8+ T-cell as well as humoral responses against specific tumor-associated anti-gens have been reported. Nevertheless, in a large majority of cases, natural immu-nity against breast cancer is not protec-tive, suggesting that breast tumors (BTs) escape immunosurveillance. In addition, several studies have demonstrated that the BT microenvironment subverts the func-tion of immune cells and favor immuno-suppression, avoiding the establishment of antitumor immunity.1 In this context, we have observed that BT infiltration by plasmacytoid dendritic cells (pDCs) is associated with an adverse clinical out-come,2 suggesting that pDCs might con-tribute to the immune evasion of BTs and ultimately to their outgrowth. Plasmacytoid dendritic cells deficient in IFNα production promote the amplification of FOXP3+ regulatory T cells and are associated with poor prognosis in breast cancer patient