The majority of diagnosed breast tumors (68%) are subtype luminal A (HR+/HER2-), followed by 10% that are triple-negative (HR-/HER2-), 10% are luminal B (HR+/HER2+), and 4% are HER2-enriched (HR-/HER2+) [5]. The gene discussed is ERBB2; the disease is breast neoplasm.