ESR1 and breast cancer: For instance, computer-assisted image analysis (CAIA) has been employed to quantify immunohistochemical stains, such as Estrogen Receptor (ER), Progesterone Receptor (PR), and Human Epidermal Growth Factor Receptor 2 (HER-2/neu) breast biomarkers, providing a standardized method for all pathologists to score IHC findings in breast cancer cases [4].