Dose response of quercetin on membrane markers expression, evaluated as CD123-PECy5 MFI, in basophils activated with 4 μg/ml anti-IgE (A), 100 nM fMLP (B), 0.5 μM calcium ionophore A23187 (C) or 50 nM PMA (D). Cells were pre-treated for 10 min at 37°C with increasing doses of quercetin, then stimulated for further 30 min at 37°C with the indicated agonists. Values are mean ± S.E.M. of triplicate assays. Figure is representative of one triplicate experiment of 4 performed for each series of different stimuli.