To assess the survival of CFU-S12 after exposure to acetaldehyde, we treated total bone marrow cells with 4 mM acetaldehyde for 4 h in vitro before injecting them into lethally irradiated recipient mice. After 12 days, the number of CFU-S were counted. Survival was expressed relative to the untreated control for each genotype. Each data point represents the mean CFU-S survival in ten recipient mice, expressed relative to untreated samples of the corresponding genotype.