We next examined HtrA1 transcript levels in 7 breast epithelial cell lines, including 5 human breast cancer (hBC) cell lines (MCF7, MDA-MB-231, MDA-MB-468, NM2C5, and M4A4), and 2 immortalized non-tumorigenic cell lines (MCF10A and MCF12A), by QPCR. Here, HTRA1 is linked to breast carcinoma.