PGR and breast cancer: Patients with basal-like breast cancer (triple negative, HER2/ER/PR-negative) have a worse prognosis than those with the luminal A (HER2-negative, ER/PR-positive), luminal B (triple positive, HER2/ER/PR-positive) or HER2 (HER2-positive, ER/PR-negative) subtypes [13–15].