Supernatant steroid concentration normalized by total protein in the founder HAC15 cell line vs mitotane-resistant and nonresistant HAC15 clones, determined by LC-MS/MS (n = 3). Steroid hormone production is largely abated in mitotane-resistant clones. Shown is mean ± s.d., (measured in triplicate) each from three clones, except for aldosterone and cortisol in resistant cells, for which results from a single clone are shown (levels from the two other clones were below detection limit). DHEA, dehydroepiandrosterone.