IL2RG and neoplasm: As few as 160 ALDH-high cells were able to generate a serially transplantable tumor in NOD/SCID/IL-2Rγ null mice, while no tumor growth was seen with 80,000 or less ALDH-low cells, and 3 of 7 mice injected with 80,000 unsorted cells grew tumor, but none grew tumor with less than 80,000 unsorted cells injected.