Relative to Luminal A breast tumors, younger women were more likely to be diagnosed with Luminal B (Odds Ratio [OR] = 2.11, p = 0.03), HER2-enriched tumors (OR = 3.27, p = 0.0007), and basal (OR 4.39, p = 0.0000005) breast cancer. The gene discussed is ERBB2; the disease is breast carcinoma.