We previously found that SerpinB2-upregulated MDA-MB-231 cells that were stably overexpressing miR200c promoted lung metastasis and boosted macrophage infiltration in tumor tissues, but the knockdown of SerpinB2 decreased lung metastasis and macrophage infiltration in xenograft mouse models [4], implying that SerpinB2 secreted by MDA-MB-231 cells may contribute to macrophage migration and polarization. Here, SERPINB2 is linked to neoplasm.