Determination of phosphorylated ERK 1/2, p38, and p65 in HeLa, SiHa and HaCaT cell treatment with pentoxifylline or cisplatin either alone or in combination. 24 hours later the cells were harvested and the phosphorylated ERK1/2, p38 and p65 proteins were determined by flow cytometry. A total of 20,000 events were registered in each test. The results represent the mean ± SD of 3 independent experiments carried out in triplicate. (*) P <0.001 vs untreated control cells. (♦) = P <0.001 vs CIS.