C Immunoprecipitation of CBL from cell lysates of CD4+T cells isolated from WT or CBLB-deficient mouse (Cblb-/-) and kept unstimulated (-) or stimulated as in (A). Immunoprecipitates and whole cell lystates (WCLs) were analyzed by immunoblot with antibodies specific for the proteins specified in the left margin. Molecular masses are shown (kDa). Data are representative of at least 2 experiments. 