HSPA5 and autosomal dominant medullary cystic kidney disease with or without hyperuricemia: The ER stress-induced chaperone 78 kDa glucose-regulated protein [GRP78; also known as binding immunoglobulin protein (BiP)] is upregulated in renal biopsies from patients harboring mutations in UMOD (Adam et al., 2012); however, mechanisms of ER stress and the UPR pathways have not been studied further in ADTKD.