RUNX1, TAL1, and KLF1 are connected in erythroid gene expression control. (A-C) Expression of TAL1, KLF1, RUNX1, GYPA, and α-Globin was determined at the mRNA level at the given time points upon TPA-induced megakaryocytic differentiation of K562 cells. (D) Binding of KLF1 to the GYPA promoter was reduced upon megakaryocytic differentiation of K562 cells. (E) Binding of KLF1 to the regulatory hypersensitive site 2 (HS2) of the Globin locus was reduced upon megakaryocytic differentiation of K562 cells. (F) Coexpression of TAL1 with RUNX1 rescued GYPA expression in wild-type K562 cells measured by FACS. (G-I) Coexpression of KLF1 with RUNX1 rescued expression of GYPA, β-Globin, and α-Globin expression in wild-type K562 cells. The P values were calculated using Student t test. *P < .05; **P < .01; ***P < .001.