DDR1 and chronic kidney disease: The lead loci in the DNCRI meta-analysis also included other collagen-related findings: association with microalbuminuria for the rs116772905 variant in the DDR1 gene encoding the epithelial discoidin domain-containing receptor 1, which binds collagens including type IV collagen; and gene aggregate analysis found variants in the COL20A1 gene associated with severe CKD.