CHI3L1 and acute kidney injury: Urine or plasma Chi3l1 can act as valuable noninvasive biomarkers for acute kidney injury (AKI); for example, the levels of urinary Chi3l1 in patients with stage Ι AKI (9.13 ± 1.22 ng/mL), stage ΙΙ AKI (11.30 ± 1.54 ng/mL), and stage ΙΙΙ AKI (13.13± 1.16 ng/mL) continue to increase [204,205,206,207].