IC50a values of DPT, PTX, and etoposide in MCF-7/S and MCF-7/A cells
↵a Drug concentration required to inhibit cancer cell proliferation by 50%. Data are expressed as the mean ± S.D. from the dose-response curves of three independent experiments.
↵b Resistance index: (IC50 of MCF-7/A cell)/(IC50 of MCF-7/S cell).