CST3 and chronic kidney disease: They also suggest use of the 2012 CKD-EPI equations (eGFRCKD-EPI-CysC, eGFRCKD-EPI-Cr-CysC) to confirm kidney function when cystatin C has been measured, particularly for patients with eGFRCr of 45–59 mL/min/1.73 m2 who do not have markers of kidney damage.