Abstract: A method of producing stem/progenitor cells from human or animal origin. A population, from an embryonic, fetal or adult source, preferably from bone marrow, blood, fat, muscle, heart, intestine, kidney, liver, lung, pancreas, skin or neural tissues, that includes stem/progenitor cells, is treated with one or more first cytostatic or cytotoxic agents to which the stem/progenitor cells are less sensitive than the other cells of the population. Preferably, the agent(s) selectively deplete(s) from the population cells that are negative with respect to expressing a transporter gene of the first agent(s) while sparing cells that are positive with respect to expressing that gene. Preferably, the population also is treated with one or more cytokines and/or growth factors.