In order to assess the role of Prss14/ST14 on the breast cancer progression and metastasis, we used two mouse breast cancer cell lines, highly metastatic 4 T1 and less metastatic E0771, and their syngeneic mouse hosts, Balb/c and C57BL/6 strains, respectively (Fig.1). The gene discussed is ST14; the disease is breast carcinoma.