In a separate experiment, we found that, similar to our previous study showing high pro-urokinase plasminogen activator (pro-uPA) expression in COX-2 overexpressing breast cancer cell lines [20], pro-uPA is overexpressed in Gln-ind cells (B Singh, AM Cady, and A Lucci, unpublished data), providing a basis of invasion into basement membrane. Here, PLAU is linked to breast cancer.