SERPINE2 and fibrosarcoma: To assess whether the anti-angiogenic and anti-tumor activity of CgA was indeed mediated by PN-1, we investigated a) the effect of siRNA-mediated PN-1 gene silencing and of anti-PN-1 neutralizing antibodies on the anti-angiogenic activity of CgA in the endothelial-sprouting assay (spheroids), and b) the effect of anti-PN-1 neutralizing antibodies on the anti-tumor activity of CgA in the WEHI-164-fibrosarcoma and TS/A adenocarcinoma models, in vivo.