DEK is required for C/EBPα–induced expression of GCSFR3 and CEBPE in vitro. K562 cells expressing control (ER) and C/EBPα mutants (WT-ER, S21A-ER, and S21D-ER) were transduced (72 hours) with lentiviral particles carrying either shRNA sequences that targeted DEK (shDEK1 or shDEK2) or an insertless construct as a negative control (KH1). (A) GFP⁺ cells (i-iv) were assessed by immunoblot for expression of DEK and C/EBPα, along with TATA-binding protein as a loading control (v). Expression of GCSFR3 (B) and CEBPE (C) mRNA in sorted populations after β-estradiol treatment for 0, 16, and 24 hours. Expression levels are normalized against mRNA expression of 36B4. Error bars indicate the SD resulting from 2 independent experiments performed in triplicate. ***P < .001; **P < .01.