ESR1 and breast cancer: However, to help demonstrate the power of cyCIF, the biomarkers were remixed into biologically relevant groups, including differentiation (CK5, CK8, and CK19), proliferation (CoxIV, PCNA, and Ki-67), microenvironmental (α-SMA, PD-1, CD4, and CD3), and breast cancer-specific (α-SMA, E-Cad, ER, CD44, and HER2) markers rather than by imaging round (Fig. 6).