Western blot analysis of wild-type and transduced cells.

Whole protein extracts obtained from CB CD34⁺ cells transduced with the LZRS-EGFP retroviral vector (lanes 1 and 2) or LZRS-Ik6-EGFP (lanes 3 and 4) and from untransduced CB CD34⁺ cells (lanes 5 and 6) are revealed with (A) an anti-Ikaros antiserum (see “Materials and methods”) or (B) an anti-Grb2 polyclonal antibody. M indicates protein markers. At least 3 isoforms of Ikaros (Ik1, Ik2, Ik6) are endogeneously produced; lanes 3 and 4 show that after retroviral transduction the relative abundance of the Ik6 isoform is greatly increased (note that for these 2 lanes the signal for Grb2 is slightly less than for other lanes).