Sgk1_i2 stimulates ENaC activity. Fisher rat thyroid epithelia were transfected with α-, β-, and γ-ENaC (0.07 μg each) and Sgk1 (Sgk1 or Sgk1_i2, as indicated, 0–0.8 μg). Total cDNA was kept constant using GFP cDNA. Amiloride-sensitive short-circuit current is plotted vs. quantity of Sgk1 cDNA (means ± SE, n = 11–18, *P < 0.002 by Student's t-test).