Conversely, the ABC group showed higher proportions of HER2-negative Luminal B (46.4 % vs. 39.8 %), HER2-positive Luminal B (15.2 % vs. 8.8 %), Enriched HER2 (10 % vs. 5 %), and triple-negative tumors (18 % vs. 13.2 %). The gene discussed is ERBB2; the disease is aneurysmal bone cyst.