Effect of KLF2 on human β-like globin gene expression at E12.5, in KLF2⁺/+globin⁺, KLF2⁺/-globin⁺, and KLF2^-/-globin⁺embryos. The percentage of globin/GPA mRNA ratio was determined, and statistical analyses were performed as described in the legend of Figure 1. (A) Embryonic ϵ-globin mRNA in the yolk sac, (B) fetal γ-globin mRNA in the yolk sac, and (C) adult β-globin mRNA in the fetal liver.