Determination of Bcl-2 and Bcl-XL anti-apoptotic proteins in cervical tumor cells treated with PTX or CIS either alone or in combination. 24 hours later the cells were harvested and the proteins expression 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 < 0.01 vs CTL. (♦) P < 0.05 vs CIS.