PGR and triple-negative breast carcinoma: Moreover, recent evidence underlined the possibility that Wnt signalling is associated with the insurgence of the immunosuppressive environment in triple-negative breast cancer (TNBC), a cluster of heterogeneous diseases that do not express oestrogen receptor (ER), progesterone receptor (PgR) and epidermal growth factor receptor-2 (HER2) and are characterized by a poor prognosis and lack of targeted treatments.