In the study by Walbaum et al. (2025) [169], the authors analyzed 658 patients with early-stage, ER-positive/HER2-negative breast cancer stratified by age (≤40, 41–50, >50), comparing clinicopathologic and genomic signatures (PAM50/Prosigna) to develop age-specific prognostic insight. The gene discussed is ERBB2; the disease is breast cancer.