Ruan et al. studied 162 patients with acute heart failure and found that increased cystatin C serum concentrations were significantly associated with increased 12-month mortality (OR 2.72, 95%CI 1.92-4.28, P = 0.017), while patients with AKI and an increased serum cystatin C had significantly higher rates of both in-hospital and 12-month mortality compared to patients without AKI (22). Here, CST3 is linked to acute kidney injury.