CST3 and chronic kidney disease: After adjusting for chronic kidney disease using multiple linear regression, creatinine (Regression coefficient 0.07, CI 95% 0.01–0.14, p = 0.022), and cystatin C (Regression coefficient 0.19, CI 95% 0.06–0.32, p = 0.004) remained independently associated with higher sNRP-1 serum concentrations in critical illness.