Assessment of effects on globin RNA levels as determined by RNAse protection. RNA from erythroblasts from BFUe's cultured in the presence of increasing concentrations of M344 was used in this experiment. Notice the increase of γ mRNA as the concentration of the compound increases in culture and the reciprocal decrease in the β mRNA. Also notice the increase in α mRNA, indicating that the compound has also nonspecific effects on globin gene expression related to the induction of terminal maturation. It is the decrease in the γ/γ + β ratio that indicates that M344 is a specific γ globin gene inducer.