(A) Representative traces of currents elicited in U87 cells using the tail voltage protocol (protocol shown on left) during acute treatment with vehicle (DMSO) and dofetilide applied to the pipette solution. (B) Absorbance at 570 nm, the readout variable from colorimetric cell proliferation assays (MTT), in U87 cells during treatment with letrozole (concentrations up to 40 μM), exemestane (up to 20 μM), and doxazosin (up to 30 μM; positive control). All data are normalized (by percentage) to the absorbance observed in vehicle-treated cells. (C) Absorbance at 570 nm in U373 cells during treatment with letrozole (concentrations up to 10 μM), exemestane (up to 10 μM), and doxazosin (up to 30 μM; positive control). *P<0.05 vs. vehicle control.