Procasp8 emerges as Lyn’s substrate within B-CLL cytosolic tyrosine phosphoproteome. (A) Cytosol purified from freshly isolated B cells from 12 B-CLL patients equally distributed between the UM-CLL and M-CLL subsets was separated by 2D-PAGE using a linear narrow range (pH 4-7) immobilized pH gradient in the first dimension for subsequent Wb analysis with anti-pTyr and anti-p-procasp8 antibodies, respectively. Blots were then stripped and reprobed with anti-procasp8 antibody. The figure, though showing the Wb patterns of patient 14, is representative of all the samples tested. (B) Whole B-cell lysates of freshly isolated B-CLL cells cultured in the absence or presence of 10 μM PP2, 7.5 μM SU6656, 0.1 μM dasatinib, or 10 nM GA at different time points underwent Wb analysis with anti-p-procasp8 and anti-procasp8 antibodies. The figures are representative of samples from 10 CLL patients belonging to 2 different subsets UM and M-CLL composed of 5 samples each.