Nur77 collaborates with Bcl-2, Bfl-1, and Bcl-B to induce apoptosis. HeLa cells in 12-well plates were cotransfected with 0.3 μg plasmids encoding either GFP or GFP-Nur77ΔDBD in combination with 1 μg plasmids encoding the 6 antiapoptotic Bcl-2 family members. After 1 day, cells were washed with PBS, fixed with 3.7% formaldehyde, and stained with DAPI to visualize nuclei by UV microscopy. The percentages of apoptotic cells were determined by counting 200 GFP-positive cells, scoring cells having nuclear fragmentation and/or chromatin condensation. Data are reported as mean ± SE (n = 3). For assessing protein expression (3 lower panels), lysates were prepared from transfected cells, normalized for total protein content, and analyzed by SDS-PAGE/immunoblotting using Bcl-2, Myc, and GFP antibodies.