Effect of Gab2 overexpression. Overexpression of Gab2 inhibits G-CSF-induced growth of Ba/F3 cells, but is not associated with inhibition of Akt or ERK. (A) Western blot of ectopically expressed Gab2 in either GR- or GRprox-expressing cells. (B) Western blots show that overexpression of Gab2 enhanced serine phosphorylation of Akt (upper panel), but not of ERK 1/2 (lower panel). (C) Growth characteristics of wild-type and truncated G-CSFR-transfected Ba/F3 cells with overexpression of Gab2 as determined by MTT cell proliferation assay.