Estrogen modulation of CK2 activity. hEVECs were shifted for 3 d to steroid-free medium (SFM) and treated with the vehicle or 10 nM 17β-estradiol (Est) for 2 d, alone or in combination with one of the indicated drugs: ICI-182,780 (ICI, 10 μM, 1 d); DRB (10 μM, 6 h); Y-27632 (Y-2, 5 μM, 6 h); and okadaic acid (OA, 10 μM, 6 h). CK2 activity was determined in cells lysates in terms of the alkaline-phosphatase-sensitive accumulation of [γ-32P]RRREEETEEE (expressed as nanomoles per minute per milligram protein [mgPr]). A, P < 0.01, compared with SFM and baseline.