CXCR4 and acute myeloid leukemia: Subsequent first-in-human studies of CXCR4-directed endoradiotherapy with 177Lu-pentixather or 90Y-pentixather in 22 patients with hematological malignancies (includes four patients with AML) have demonstrated the feasibility of this approach when combined with high-dose chemotherapy as part of a conditioning regimen for autologous or allogeneic stem cell transplantation (137, 138).