The guidelines suggest that cystatin C-based equations have the potential to improve the diagnosis and epidemiology of CKD and should only be used in individuals with an eGFR between 45 and 59 ml/min/1.73 m2 with no other evidence of CKD [8], suggests limited availability of eGFR assessments rather than poor performance. The gene discussed is CST3; the disease is chronic kidney disease.