Determination of phosphorylated p65 (NF-κB subunit) in U937 cells treated with PTX, MG132 and PTX + MG132. U937 cells were incubated either alone or treated with 8 mM PTX, 1 μM MG132, or PTX + MG132. After 1 hour, the phosphorylated p65 protein was determined by flow cytometry. For each sample at, least 20,000 events were acquired. The results represent mean ± standard deviation of the Mean Fluorescence Intensity (MFI) of phosphorylated p65 of three independent experiments carried out in triplicate. *p < 0.01 vs the untreated control group.