In essence, the current study addressed (1) whether CN-1 can be reliably measured in spot urine, (2) whether there is an association between urinary CN-1, eGFR, and albuminuria in diabetic and nondiabetic patients with chronic kidney disease, (3) whether high urinary CN-1 concentrations in macroalbuminuric patients are associated with low CN-1 concentrations in serum, and (4) whether the (CTG)n polymorphism known to determine CN-1 secretion is associated with urinary CN-1 concentrations. The gene discussed is CNDP1; the disease is chronic kidney disease.