ESR1 and breast carcinoma: Furthermore, we found that median OS durations in patients with ER+ breast cancer receiving tamoxifen were longer when MYC expression levels (where the cutoff point is 0.71) were lower (median OS, 79.8 months for high MYC expression group and not reached for low MYC expression group; HR, 1.49; 95% CI, 1.07–2.08; p = 0.0177) (Figure 1f).