KLF2 suppresses nuclear localization of phosphorylated ATF2. HUVECs transduced with mock (A,C,E) or KLF2 (B,D,F) lentivirus were fixed with paraformaldehyde and stained for Thr71-phosphorylated ATF2 protein by immunofluorescence (A-B). Nuclei were made visible with a Hoechst nuclear staining (C-D), and the pictures were merged (E-F). Photographs representative for 2 independent experiments were obtained by fluorescence microscopy using a magnification of × 63. (G) Quantification was performed by counting nuclei with strong nuclear pATF2 positivity in 3 representative microscopic fields from mock- and KLF2-transduced cells taken from the 2 independent experiments, with each field containing an average of about 350 cells. **Significant difference in pATF2-positive nuclei between mock and KLF2 values (P < .01).