This study also has other limitations. Due to the lack of clinical data of some patients, there is no complete data of NGAL, KIM-1, IL-18, and other biomarkers to make a horizontal comparison with FST. Moreover, because of the limited number of patients with AKI stage 3, there is a lack of sufficient independent cohort to verify the effectiveness of the results. Here, LCN2 is linked to acute kidney injury.