The invention provides compositions and methods useful for the depletion of CD117+ cells and for the treatment of various hematopoietic diseases, metabolic disorders, cancers, and autoimmune diseases, among others. Described herein are antibodies, antigen-binding fragments, ligands, and conjugates thereof that can be applied to effect the treatment of these conditions, for instance, by depleting a population of CD117+ cells in a patient, such as a human. The compositions and methods described herein can be used to treat a disorder directly, for instance, by depleting a population of CD117+ cancer cells or autoimmune cells. The compositions and methods described herein can also be used to prepare a patient for hematopoietic stem cell transplant therapy and to improve the engraftment of hematopoietic stem cell transplants by selectively depleting endogenous hematopoietic stem cells prior to the transplant procedure.