Expression of transgenic Ik6 in transduced CB cells. Protein extracts of transduced EF1 GFP or EF1 IK6 CB cells were immunoprecipitated at day 7 with an anti-Flag epitope antibody, and analyzed by Western blotting with anti-Ikaros antibody. Arrows indicate the position of Ik1 and Ik6 immunodetected proteins.