PLAUR and neoplasm: Although there were no significant differences in tumor growth between control and shuPAR groups (Figure 5B–D), spontaneous lung metastases (measured between 42 and 45 days after tumor implantation) were dramatically reduced in uPAR knockdown groups (p < 0.05; n = 5/group) (Figure 5A–D), suggesting that uPAR mainly plays a role in the post-intravasation processes of metastasis but not the primary tumor growth.