Updated project metadata. A new method of graft manipulation based on physical removal of αβ+ T cells and CD19+ B cells, leaving mature NK cells and γδ T cells in the graft, has been recently developed for HLA-haploidentical HSCT. We demonstrated that γδ T cells collected from transplanted patients are endowed with capacity of killing leukemia cells after ex vivo treatment with zoledronic acid (ZOL). Thus, we hypothesized that infusion of ZOL in patients receiving this type of graft, may boost γδ T cell cytotoxic activity against acute leukemia blasts.