CHI3L1 and acute kidney injury: We found a modest association between high levels of YKL-40 and AKI progression or death—patients with YKL-40 ≥ 5 ng/ml had a three-fold increase in the odds of this outcome.In addition, adding YKL-40 ≥ 5 ng/ml to our baseline clinical model significantly improved risk reclassification primarily for patients who would not develop the primary outcome.