To address the mechanistic role of Klf4 in Prmt1-mediated gene expression, stable E14 cell lines with ectopic expression of Klf4 were generated by infection with lentiviral vectors expressing FLAG-Klf4 (designated Klf4-1 and Klf4-2), with a GFP lentiviral vector as a control. The gene discussed is KLF4; the disease is infection.