Although a previous report suggested that expression of COX7AR was inducible by estrogen signals5, the qRT-PCR result indicated that COX7AR is also highly induced in some ER-negative, highly-malignant breast cancer cell lines, such as the triple-negative breast cancer cell lines BT20 and MDA-157 (Fig. 1c). Here, COX7A2L is linked to breast carcinoma.