Immunofluorescence assay was performed, as described previously[9 (link),12 (link),19 ]. Briefly, cells were cultured (5 × 104 cells in 0.2 mL of RPMI 1640/well) in microslides coated with poly-D-lysine (Santa Cruz). After stimulation with BFT for the indicated period, cells were treated with goat anti-HO-1 and rabbit anti-phospho-Nrf2 Abs as primary Abs for 2 h. Cells were then treated with Alexa fluor 488-conjugated secondary Ab (green color) against goat IgG and DyLight 549-conjugated secondary Ab (red color) against rabbit IgG for 1 h. Images were captured using a fluorescence microscope (DMI4000B, Leica Microsystems GmbH, Wetzlar, Germany)[9 (link),12 (link),19 ].