The level of endoglin was measured in two series in 11 patients with familial hypercholesterolemia. Significant decrease of level was found after extracorporeal elimination; it was after rheopheresis in 3 patients 28.410.74/34.375.57% (after the first and second serie) and after LDL-apheresis in 8 patients 21.229.05/17.843.20%.