Not only is the Arabian horse a non-rodent, large animal that can be used to enhance our understanding of the hematopoietic system, but its susceptibility to SCID and its long life span also make it optimal for SCID research. Since adverse events (such as the development of leukemia) can unfortunately arise in bone marrow treatment for SCID, this non-traditional research model can be used to test the efficacy and safety of alternative therapies, like gene therapy and stem cell transplantation, before being clinically implemented in humans.