Allogeneic cells are cells that are derived from a donor of the same species but are genetically different from the recipient. These cells can come from various sources, such as bone marrow, peripheral blood, or umbilical cord blood. They are often used in medical treatments, particularly in stem cell transplants for conditions like leukemia or other blood disorders. In allogeneic transplants, the recipient's immune system may recognize the donor cells as foreign, which can lead to complications like graft-versus-host disease (GVHD). Despite this risk, allogeneic cells can provide significant benefits, including a broader range of immune responses and the potential for treating diseases that the recipient's own cells cannot address.