Comparison of histone acetylation profiles of K562 and fetal liver cells. (A) Comparison of histone acetylation in fetal liver (∼day 100; ▒) and hemin-induced K562 cells (■). Notice that acetylation level of histone H3 in K562 cells generally is lower than that in primary fetal erythroid cells when using a common reference gene (mAmy). (B) Comparison of histone acetylation between uninduced (hatched) and induced (black) K562 cells. The levels of histone acetylation are unchanged upon hemin induction, except that exon 2 of the γ gene is acetylated to a slightly higher level after induction.