Urinary NGAL has been established as an early responding biomarker of AKI, not only in rats following early ischemic AKI and in mice from cisplatin toxicity (Mishra et al., 2003, 2004), but also in both adult and pediatric patients after cardiac surgery (Mishra et al., 2005; Wagener et al., 2006), and in critically ill children with heterogeneous illness (Zeid et al., 2019). Here, LCN2 is linked to acute kidney injury.