NDUFV1 and cystic teratoma: Semi-quantitative assessment of NDUFV1 staining by pathologists yielded negative scores of 2 × 2 = 4 (2 in intensity, 2 in proportion of the positive cells: 10–50%) for the stroma of normal ovary (Fig. 5A) and positive scores of 3 × 2 = 12 (3 in intensity, 4 in proportion of the positive cells: >80%) for the parenchyma of mature cystic teratoma of the ovary, Tera-2 (Fig. 5B).