WNK4 and Gordon syndrome: In Gordon syndrome (right panel), the pink arrows represent an increased abundance of mutant WNK1 and wild-type WNK1 and WNK4 and the green arrows (marked +) indicate increased expression of NCC on the apical membrane of the distal convoluted tubule (DCT), NKCC1 on the basolateral membrane of the collecting duct (CD), and NKCC2 on the apical membrane of the thick ascending loop of Henle (TAL).