RecruitingPhase 1Drug trialExpanded/Activated Gamma Delta T-cell Infusion Following Hematopoietic Stem Cell Transplantation and Post-transplant CyclophosphamideGamma delta T-cells are part of the innate immune system with the ability to recognize malignant cells and kill them. This study uses gamma delta T-cells to maximize the anti-tumor response and minimize graft versus host disease (GVHD) in leukemic and myelodysplastic patients who have had a partially mismatched bone marrow transplant (haploidentical).