Abstract: Described herein are methods of promoting engraftment of a cell transplant and methods of killing hematopoietic stem cells by administering a population of T cells, NK cells or cytotoxic immune effector cells comprising a cell-surface receptor for a stem cell-specific antigen. Also described herein is a composition comprising T cells, NK cells or cytotoxic immune effector cells genetically modified to encode a cell-surface receptor for a stem cell-specific antigen.