A paper in J Drug Target shows a nice property of a cell line
Eight repeats of the glucocorticoid response element (GRE) were cloned into […] vector, and the resulting recombinant plasmid […] was stably transfected into the 293E cells. The stable and sensitive cell line […] was selected by dexamethasone (DEX) using fluorescent microscopy and fluorescence-activated cell sorting. […] The expression of GFP4 in the cell line was under the control of GRE, up-regulated by DEX treatment and down-regulated by phorbol myristate acetate (PMA).
as it could be nicely used for the steroid activity of any compound.