NIH-pJ5W-Ha-Ras(61L) cells were grown in 0, 5, or 10 μM dexamethasone for 24 h and then assayed for levels of Ras-GTP using either a biochemical (A) or immunocytochemical (B–I) assay. A, cells treated with 5 μM dexamethasone demonstrated a 0.8–1.2-fold increase in Ras-GTP (range over three experiments; 0.8-fold shown here), while cells treated with 10 μM dexamethasone had a 3.2–3.5-fold increase (3.2-fold shown here). B and C, cells grown in the absence of dexamethasone; D and E, cells grown in 5 μM dexamethasone; F and G, cells grown in 10 μM dexamethasone; H and I, cells grown in 10 μM dexamethasone but probed with GST in place of Raf1-RBD-GST.