Compared to luminal A BC, parous women were more likely to develop HER2+ BC at age 35 and 55 (OR = 1.44, CI 1.02–2.03, p = 0.037 and OR = 1.42, CI 1.04–1.96, p = 0.029, respectively), while an inverse association was observed at age 75 (OR = 0.67, CI 0.67–0.98, P = 0.041, Table 3). The gene discussed is ERBB2; the disease is breast cancer.