As opposed to autologous stem cells, allogeneic stem cells are harvested from another patient, who stands as the donor to a patient needing a stem cell transplant.
The Basics of Stem Cells Research

Allogeneic Stem Cell Transplants
As opposed to autologous stem cells, allogeneic stem cells are harvested from another patient, who stands as the donor to a patient needing a stem cell transplant.
Allogeneic Stem Cell Transplants