PGR and cancer: Yezhelyev et al.[67] extended this approach to selectively label MCF-7 and BT-474 BC cells for HER2, epidermal growth factor receptor (EGFR), estrogen receptor (ER), progesterone receptor (PR), and mammalian target of rapamycin (m-TOR) by visible and NIR QDs which indicated that QD-based nanotechnology is an efficient approach to offer multiplexed cancer biomarker imaging in situ on intact tumor tissue specimens for tumor pathology study at the histological and molecular levels simultaneously[20-22].