 That event made him aware of the possibility and necessity of developing active and adoptive immunotherapy and applying it to the treatment of cancers.He also participated with René Kuss and Marcel Legrain in 1960 and 61 to the first successful kidney grafts between non related donors and hosts.By 1963 he "shook the medical world" when he announced he had cured a patient of leukemia by means of a bone marrow transplant.