Unlike the stochastic model, which claims the equal potential of all cells contained in a tumor mass to initiate carcinogenesis, Bonnet and Dick in 1997 first reported that only CD34+/CD38– cells from patients with acute myeloid leukemia (AML) could provoke hematopoietic malignancies in immunodeficient mice [2]. Here, CD38 is linked to acute myeloid leukemia.