Increased expression of long WNK1 (L-WNK1) specifically in the distal convoluted tubule is key to the pathogenesis of familial hyperkalaemic hypertension (FHHt), according to new research. Using a new mouse model of WNK1-associated FHHt, Vidal-Petiot and colleagues found that increased expression of L-WNK1 in the distal convoluted tubule stimulated the activity of the Na–Cl cotransporter but did not alter the activity of the epithelial sodium channel, suggesting that other pathways are responsible for the hyperkalaemia and acidosis of this model.