To determine whether mir-497-5p directly targets KCa3.1 in angiosarcoma, we first studied the expression of miR497-5p and KCa3.1 in tumor cell lines and primary endothelial cells, including ISO-HAS angiosarcoma cells, human hemangioma endothelial cells (hHVECs), human microvascular endothelial cells (hMVECs), and human umbilical vein endothelial cells (hVECs). This evidence concerns the gene KCNN4 and hemangioma.