OV2008 (p53 wt/platinum sensitive), OV2008/C13 (p53 wt/platinum resistant), and SKOV‐3 (p53 null/platinum semi‐resistant) cells were cultured in the presence of DMSO (vehicle), 10, 20, or 30 μM mifepristone for 7 days. The values of concentrations of the drug causing 50% inhibition of growth (GI50) were calculated using software (Calcusyn, Biosoft) designed to study drug interaction that analyzes the median effective dose or Dm, which is analogous to the GI50. The experiments were run 3 times in triplicates for each cell line.