Patients ≤ 40 years of age had the highest percentage of HR+/HER2+ (18.07%), HR-/HER2+ (6.71%), and HR-/HER2- (18.35%) breast cancer molecular subtypes, whereas patients >80 years of age had the highest percentage of the HR+/HER2- (80.23%) breast cancer. The gene discussed is ERBB2; the disease is breast carcinoma.