Urinary neutrophil gelatinase associated lipocalin (NGAL) concentrations in combination with urinary creatinine concentrations were associated with rapid loss of renal function and ESRD in a cohort of 158 patients at stage 3 and 4 of CKD.[31] However, a larger study on >3000 patients did not show a substantial benefit of urinary NGAL concentrations as a predictor when added to known parameters such as proteinuria in CKD patients for adjustment.[16] Urinary cystatin C has not been extensively studied in this context. The gene discussed is CST3; the disease is chronic kidney disease.