PRSS8 and breast carcinoma: In experimental studies on breast cancer cell lines by Chen and Chai [18], it has been shown that prostasin mRNA and protein were expressed in normal human mammary epithelial cells (NHMEC), the poorly invasive breast carcinoma cell line MCF-7, and the nonmetastatic breast carcinoma cell line MDA-MB-453, but absent in highly invasive and metastatic breast carcinoma cell lines MDA-MB-231 and MDA-MB-435s.