Hypokalemia activates the renal sodium chloride cotransporter (NCC) along the distal convoluted tubule (DCT), at least in part, through with-no-lysine 4 (WNK4) kinase and STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) signaling. The gene discussed is STK39; the disease is Hypokalemia.