Left: Regulation of the PT cell Na⁺-P_i cotransporter Npt2a by PTH, via apical and basolateral PTH receptors. As reported in this issue by Weinman et al. (1), phosphorylation at Ser77 of NHERF-1 results in a dissociation of Npt2a from NHERF-1, consequent Npt2a internalization, and an increased excretion of phosphate in the urine. Right: DCT cells express the Na⁺-Cl^– cotransporter NCC, which is inhibited by thiazides. The study by Yang et al. (2) in this issue of the JCI reports that WNK3, a member of the WNK kinase family, interacts with WNK1 and WNK4 to regulate the phosphorylation and activity of NCC. WNK kinases are regulated by stimuli such as changes in aldosterone or extracellular potassium levels. Dotted arrows indicate that the nature of interaction between kinases (direct or indirect) is not known to date. KS-WNK1, kidney-specific WNK1.