Although there is potential harm associated with overdiagnosis of CKD in older adults, CKD should be properly diagnosed and risk stratified in older adults using all available measurements, including cystatin C testing in those with a serum creatinine-based eGFR of 45–59 mL/min per 1.73 m2 and ACR < 30 mg/g [34]. This evidence concerns the gene CST3 and chronic kidney disease.