 These ligands are referred to as antagonists.An example of antagonistic nuclear receptor drug is mifepristone which binds to the glucocorticoid and progesterone receptors and therefore blocks the activity of the endogenous hormones cortisol and progesterone respectively.Antagonist ligands work by inducing a conformation of the receptor which prevents coactivator and promotes corepressor binding (see lower half of the figure to the right).