KDR and neoplasm: In CRC, tumor cell-secreted exosomal miR-25-3p can directly silence KLF2 and KLF4 to downregulate the expression of vascular endothelial growth factor receptor 2 (VEGFR2), ZO-1, occludin and Claudin5 in endothelial cells and finally induce angiogenesis and vascular permeability (Zeng et al., 2018).