The subgroup analysis of BCIRG-006 trial demonstrated a high 5-year DFS rate (84%) with adjuvant AC-T regimen (doxorubicin and cyclophosphamide followed by docetaxel) in patients with small (< 2 cm) HER2 + breast cancer, but the addition of trastuzumab (AC-TH) only increased 5-year DFS rate by 3% [6]. The gene discussed is ERBB2; the disease is breast cancer.