Survival coding in the analysis: patients aged below 50, 1 and above 50, 0; ER/PR: ≤20, 1 and >20, 0; treatment: endocrine, 1 and chemoendocrine, 0; tumor size: T2 + T3 + T4, 1 and T1, 0; node status: node positive, 1 and node negative, 0; grade: grade 3, 1 and grade 1 and 2, 0; CAB risk score: high‐risk score, 1 and low‐risk score, 0. The gene discussed is ESR1; the disease is neoplasm.