CHI3L1 and acute kidney injury: Children with CHI3L1 levels in the highest quartile were more likely to have AKI (p = 0.034), and there was a strong relationship between CHI3L1 and severity of AKI with 5.9% of children with CHI3L1 levels in the lowest three quartiles having stage 3 AKI compared to 28.2% of children with CHI3L1 levels in the highest quartile having stage 3 AKI (p < 0.0001).