PGR and breast cancer: Histological evaluation of hormone receptors (ER: estrogen receptor; PgR: progesterone receptor; and androgen receptor: AR), human epidermal growth factor receptor 2 (HER-2), Ki67, and tumor immunity-related biomarkers (programmed death-ligand 1; PD-L1, tumor-infiltrating lymphocyte; TILs) of breast cancer tissues have been described previously [9, 23].