We used Cox proportional hazards regression to compute the hazard ratios (HRs) and 95% simulation intervals (SIs) associating each biomarker with recurrence, with bias adjustment to account for mismeasurement of biomarker expression and baseline selection bias from tumor sample availability.<h4>Results</h4>Among ER+/TAM + breast cancers, 24% had any HSD17B1 expression compared with 13% of ER-/TAM - breast cancers. The gene discussed is ESR1; the disease is breast cancer.