The ER stress-inducible, secreted ER chaperones, including MANF, ERdj3, ERdj4, PDIA3, as well as other ER stress-dependent highly soluble proteins, including CRELD2 and angiogenin (Table 1), may provide a valuable tool in the investigation of disease pathogenesis, early diagnosis, risk stratification, treatment response monitoring, and development of targeted therapies for rare kidney diseases. Here, CRELD2 is linked to kidney disorder.