CST4 and chronic kidney disease: Several papers have reported improved discrimination if eGFRcys is used in risk prediction analyses instead of eGFRcreat, though it is unclear whether this is due to improved GFR estimation or associations with the non-GFR determinants of cystatin C. In our cohort, eGFRcys did not improve discrimination in risk prediction analyses for CKD progression or all-cause mortality, suggesting that widespread use in primary care will not improve risk prediction [15,16].