Comparison of candidate globin transcription factor expression levels using oligonucleotide arrays. Array signal intensities graphed according to cultured erythroblasts day 7 RNA pool for (A) GATA-1, (B) p45 NF-E2, (C) EKLF (KLF1), (D) BCL11A, and (E) SOX6 are shown. The lines connect the normalized intensity values from each of the 5 matched pools (3 separate donors per pool, x-axis) of RNA from day 7 cultured erythroblasts expressing low-HbF (■) versus high-HbF (○).