MKI67 and breast cancer: In alignment with our previous work in a different breast cancer cohort (23), we identified expected phenotypes such as CK5+ and CK14+ basal cells, apoptotic cells, Ki67+ proliferating cells, HER2-high cells, and various luminal cell phenotypes characterized by GATA3, varying levels of E-cadherin, cytokeratins (CK7, CK8/18/19), and hormone receptor expression.