Deacylcortivazol (DAC) is a potent glucocorticoid. When incubated with glucocorticoid-resistant mutants derived from the glucocorticoid-sensitive human leukemic cell line CEM-C7, DAC caused significant growth inhibition. The cytotoxicity of DAC at concentrations higher than necessary for glucocorticoid receptor saturation is not mediated by glucocorticoid receptors.