Dual-labeling for uromodulin and the ER marker calnexin showed that the intracellular uromodulin in Umod+/125R and Umod125R/125R kidneys was colocalized with the ER (Fig. 1F), as previously demonstrated both in vitro (Williams et al., 2009) and in ADTKD-UMOD patients (Bernascone et al., 2010), and consistent with the presence of the lower molecular mass precursor detected by western blotting (Fig. 1C). Here, CANX is linked to autosomal dominant medullary cystic kidney disease with or without hyperuricemia.