Expression of HA-tagged A1 in stable transfectants. 32D cl3 cells were transfected with pcDNA3-HA-Bfl1 as described, and G418-resistant clones were isolated. Western blotting with an antibody against the HA tag was performed on total cellular protein from 3 of these transfectants: 32DA1.1 (Lane 2), 32DA1.2 (Lane 3), and 32D A1.3 (Lane 4), as well as protein from untransfected 32D cl3 cells (Lane 1). The arrow indicates the presence of HA-tagged A1 in the transfected cells but not in the parental cells. Molecular-weight markers are shown in the lane marked MW.