Based on previous data that HIF-1α inhibition by echinomycin preferentially target leukemia-initiating cells without adverse effects on hematopoietic stem cells [28], we further hypothesize that HIF-1α inhibition is a promising prophylactic strategy that not only reduces aGVHD and preserves GVL but also preferentially targets leukemia-initiating cells that helps to further reduce the risk of leukemia relapse. The gene discussed is HIF1A; the disease is leukemia.