WNK1 and Hyperkalemia: KS-WNK1–KO mice also exhibited higher pNCC abundance than WT controls following 10 days of potassium loading on a high KCl (5% potassium) diet (Supplemental Figure 4, A–C), which was sufficient to induce frank hyperkalemia in the absence of amiloride (Supplemental Figure 4, D and E).