PECAM1 and neoplasm: Compared with the tumor burden mice injected with MDA-MB-231 cells and CAFs, the tumor burden mice injected with MDA-MB-231 cells mixed with FOSL2-silenced CAFs had fewer blood vessels on the tumor surface and less CD31 staining in tumor tissue; the tumor burden mice injected with a mixture of MDA-MB-231 and FOSL2-overexpressing NFs had more blood vessels and a large tumor size (Figure 8A and Figure S6A).