ESR1 and neoplasm: When potentially confounding factors were included in multivariate assessment (tumour size, grade, nodal stage, vascular invasion status, ER, PgR, and HER2 status), low cytoplasmic expression of CYP2S1 was significantly independently associated with adverse survival (hazard ratio [HR]: 0.639; 95% confidence interval [CI]: 0.483–0.846; p = 0.002) (Table 3).