GSTM1 and benign muscle neoplasm: The EBL (< 5 cm, 630.4 cc vs 5–10 cm, 733.3 cc vs. ≥ 10 cm 900.0 cc, p <0.001), differences of Hb (< 5 cm, 1.7 mg/dL vs 5–10 cm, 2.0 mg/dL vs ≥ 10 cm, 2.5 mg/dL, p = 0.04), postoperative transfusion rate (< 5 cm, 26.1% vs 5–10 cm, 45.1% vs ≥ 10 cm, 81.8%, p <0.001) were increased depending on the myoma size.