Key role of microRNA-15a in the KLF4 suppressions of proliferation and angiogenesis in endothelial and vascular smooth muscle cells.

•This is the first demonstration that miR-15a is a novel target gene of KLF4.•A novel finding that KLF4 increases the expression of miR-15a in ECs and VSMCs.•The novel mechanism is that KLF4 inhibits the proliferation of ECs via miR-15a.•The novel mechanism is that KLF4 inhibits the proliferation of VSMCs via miR-15.•miR-15a mediates the anti-angiogenic activity of KLF4.