S100A4 and cancer: To further determine the hypothesis that this effect was due in part by the presence of extracellular S100A4, we treated animals bearing tumors from cells overexpressing S100A4 with the 5C3 monoclonal antibody, obtaining a remarkable reduction in tumor growth and tumor angiogenesis, thus indicating the importance of S100A4 on tumor development and confirming that therapies using antibodies against S100A4 can be promising strategies to treat cancer.