Schematic of competitive repopulation assay. Test cells from the BM of FancC −/− and FancC +/+littermates were isolated and enriched for Sca1⁺lin^−/dim cells. Each respective test cell population was cotransplanted into irradiated recipient mice with competitor cells from B6.BoyJ mice that were genetically identical to C57Bl/6 mice with the exception of expression of a different CD45 isoantigen.