Gab2-dependent inhibition of BCR-ABL-mediated cell proliferation. (A) The histogram of RFP fluorescence from 3 independent TonB-Gab2 shRNA clones is shown with high (black line), medium (light gray line), and low (dark gray line) RFP fluorescence. (B) Cellular lysates from the 3 TonB-Gab2 shRNA clones were subjected to immunoblotting with anti-Gab2 and anti-ERK2 antibodies as loading control as indicated. (C) Number of trypan blue-negative TonB-Gab2 shRNA cells in the presence of IL-3 (left) or doxycycline in the absence of IL-3 (right). Triangles depict cell numbers of a control TonB-GL4 shRNA clone with high RFP expression, which was set to 100% on day 14.