ROMK was originally suspected to be inhibited in PHAII due to the low Na+ delivery to the lumen because of the NCC overactivation [78]; however, recent studies reported that ROMK is inhibited by PHAII mutant, WNK4, via clathrin-dependent endocytosis, causing hyperkalemia in PHAII, and is not related to WNK4 kinase activity [79]. This evidence concerns the gene KCNJ1 and Hyperkalemia.