FLT1 and neoplasm: Specifically, VEGFA and VEGFR1 were highly expressed in tumor cells, VEGFR1 and VEGFR2 in endothelial cells, and PLGF in fibroblasts and smooth muscle cells, respectively (Figure 6G), suggesting the crosstalk between tumor cells and fibroblasts or endothelial cells in tumor microenvironment through these ligand-receptor pairs, which mediated in the tumor angiogenesis and metastasis.