Western blot analysis of pSTAT-3 and pSTAT-5. Immunoblotting (upper panels) and densitometric analysis (lower panel) of pSTAT-3 (A) and pSTAT-5 (B) expression. Mononuclear cells were obtained from bone marrow of 5 healthy controls, 5 patients with PV, and 5 patients with ET. Immunoblots refer to a representative experiment. Values of densitometric analysis in PV and ET are normalized for results obtained in healthy controls (mean values of 5 experiments for each set of samples). SD are less than 10% and have been omitted.