FOXO4 and lung adenocarcinoma: Dex did transcriptionally activate both FOXO3 and FOXO4 in all of the lung adenocarcinoma cell lines in this study except for the parental (low GR) H1299 cells; the mRNAs for FOXO3 and FOXO4 in all of the sensitive cells increased within 24 h of Dex treatment and reached plateau levels by 3 to 7 days of treatment (Fig. 6A and B).