After conjugation of QDs with antibodies such as anti-HER2, EGFR, and mTOR antibodies, the cancer cell lines were nurtured with QD-Ab conjugates for one hour by Yezhelyev et al. Cell lines were marked with five different kinds of QDs, and it was found that the cancer biomarkers were present either on the cell membrane or in the nucleus of the cell. The gene discussed is ERBB2; the disease is cancer.