Patients with stage 4 CKD defined by creatinine alone appearedto behave more alike those with less severe CKD (stage 4_neither), while studiedoutcomes in patients with stage 4 CKD defined by cystatin C alone were similar tothe more severe group defined as CKD stage 4 by both cystatin C and creatinine. Here, CST3 is linked to chronic kidney disease.