EFNA3 and angiosarcoma: • miR-210 was downregulated in vivo and in vitro in angiosarcoma cells.• E2F3 and ephrin A3 were upregulated in angiosarcoma tumor cells.• Angiosarcoma cell numbers decreased significantly after E2F3 or ephrin A3 knockdown.• Angiosarcoma patients not significantly differed from healthy controls in serum miR-210 levels.