Material and Method: The breast carcinoma samples (n = 26) with medullary pattern (defined according to established criteria) were subjected to immunohistochemical assays of the following receptors: ER, PR, HER2/neu, Ki-67, p53, Bcl-2, VEGF, MMP1, E-cadherin, EGFR, Hsp70, Hsp90, CD20, CD3, CD4, CD8, CD68, CD163, CD56, CD138, MPO, S100, IgG, IgM, and PD-L1. The gene discussed is PGR; the disease is breast carcinoma.