PGR and breast cancer: Interpreting from the division of BC, 5/23 (21.73%) SP-positive cases belonged to the luminal A group (ER/PR+, HER2-), 14/23 (60.8%) cases belonged to the luminal B (ER/PR+, HER2+) group, and 4/23 (17.39%) cases belonged to the ER/PR- and HER2+ group of BC (Table 3).