Analysis of tyrosine-phosphorylated proteins in platelets and lymphocytes. (A-C) Evaluation of resting platelet lysates was done in members of the SRC-RT pedigree carrying the Src p.E527K variant (patients 3, 6, and 7), in parallel with those of 2 controls. αIIb was used as loading control. *P ≤ .05 between patients and controls. (A) Representative image of immunoblotting experiments of SRC and phospho-SRC (P-SRC), and densitometric analysis of the bands obtained with 2 separate experiments (mean ± standard deviation). (B) Representative image of immunoblotting experiments of BTK and phospho-BTK (P-BTK), and densitometric analysis of the bands obtained with 2 separate experiments (mean ± standard deviation). (C) Representative image of immunoblotting experiments of PLCγ2 and phospho-PLCγ2 (P- PLCγ2), and densitometric analysis of the bands obtained with 2 separate experiments (mean ± standard deviation). (D) Flow cytometric evaluation of SRC downstream targets in B (CD19⁺) lymphocytes. Phosphorylation of tyrosine kinases were analyzed in unstimulated cells (white bars) or after stimulation with anti-IgM (black bars) in Src p.E527K carriers (patients 3 and 9) and control lymphocytes (n = 2) by flow cytometry. Data are representative of 2 individual experiments. Results reflect mean ± standard deviation values. AU, arbitrary units; FI, fluorescence intensity. *P ≤ .05 between stimulated and unstimulated samples.