In a pilot clinical trial in refractory hematologic malignancy subjects, we have found that augmentation of a T cell-replete allograft with donor Th2 cells generated ex vivo in sirolimus (rapamycin; Th2.rapa cells) allows prompt donor engraftment after outpatient-intensity chemotherapy. This transplant approach has been associated with a low incidence of acute graft versus host disease (GVHD).