Classification of breast cancer biomarkers and assay profiling. T47D cell line is from the human breast cancer cells, and OVCAR 3 cell line is from the human ovarian cancer cells. The scheme shows the basic concept for the classification of biomarkers discussed in this paper. EpCAM (epithelial cell adhesion molecule), EGFR (epithelial growth factor receptor), HER-2 (human epidermal growth factor receptor 2), PD-L1 (programmed death-ligand 1), PD-1 (programmed cell death protein 1), CA-125 (cancer antigen, 125), ER (oestrogen receptor), PR (progesterone receptor).