ESR1 and neoplasm: Molecular markers were differentially associated with CEM accuracy: progesterone receptor positivity (95% CI: 1.47 to 5.68, p = 0.0002), higher Ki67 proliferation index (95% CI: 0.58 to 5.02, p = 0.0235), HER2 positivity (95% CI: 0.49 to 2.45, p = 0.0145), and higher tumor grade (95% CI: 0.47 to 2.47, p = 0.0065) correlated with increased measurement error, whereas estrogen receptor status did not (95% CI: 0.28–2.06, p = 0.08) (Table 6).