We attempted to supplement previous findings by including three recent RCTs (EARLY-RRT, 2018 [59]; FST trial, 2018 [58]; and IDEAL-ICU, 2018 [57]) in this meta-analysis to examine the effect of early RRT initiation in the AKI population with high plasma NGAL, and we assessed the safety of the watchful waiting strategy in this population. Here, LCN2 is linked to acute kidney injury.